Creating an if statement when a radio button is clicked in rails

I'm creating an app with Ruby on Rails 4, I'd like to avoid using JavaScript for this if at all possible. I'm trying to create an if statement that reveals a div only when one of the radio buttons is selected. I've tried a few different ways but I'm getting errors, I thought this should work:

<% if options[1] == true %>
 #do something
<% end %>

Also tried:

<% if options[1], :checked => true %>
#do something
<% end %>

I'm getting multiple errors each time so I think I'm doing it completely wrong, but I can't find much in the rails guide on if statements for radio buttons.

Here is my radio button div:

  <div class="radio">
    <% @kind_options.each do |options| %>
    <label>
    <%= f.radio_button :kind, options[1], :checked => true %>
    <%= options[0] %>
    </label>
    <% end %>
  </div>

and my question_controller.rb:

class QuestionsController < ApplicationController
  before_action :set_question, only: [:show, :edit, :update, :destroy]
  before_action :set_poll
  before_action :set_kind_questions
  before_action :authenticate_user!, except: [ :index ]


  # before_action :admin!, except: [ :index ]

  # GET /questions
  # GET /questions.json
  def index
    @questions = Question.all
  end

  # GET /questions/1
  # GET /questions/1.json
  def show
  end

  # GET /questions/new
  def new
    @question = @poll.questions.build
    1.times { @question.possible_answers.build }
  end

  # GET /questions/1/edit
  def edit
  end

  # POST /questions
  # POST /questions.json
  def create
    @question = @poll.questions.build(question_params)
    @question.title = @question.title.censor

    respond_to do |format|
      if @question.save
        format.html { redirect_to @poll, notice: 'Question was successfully created.' }
        format.json { render :show, status: :created, location: @question }
      else
        format.html { render :new }
        format.json { render json: @question.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /questions/1
  # PATCH/PUT /questions/1.json
  def update
    respond_to do |format|
      if @question.update(question_params)
        format.html { redirect_to @question, notice: 'Question was successfully updated.' }
        format.json { render :show, status: :ok, location: @question }
      else
        format.html { render :edit }
        format.json { render json: @question.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /questions/1
  # DELETE /questions/1.json
  def destroy
    @question.destroy
    respond_to do |format|
      format.html { redirect_to @poll, notice: 'Question was deleted.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_question
      @question = Question.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def question_params
      params.require(:question).permit(:title, :kind, :poll_id, { possible_answers_attributes: [ :title, :question_id ] })
    end

    def set_kind_questions
      @kind_options = [
        ["Open Answer", "open" ],
        [ "Multiple Choice", "choice" ],
      ]
    end

    def set_poll
      @poll = Poll.find params[:poll_id]

    end

    # devise authenication
    def admin!
      authenticate_user!

      redirect_to root_path, notice: "Please log in as an administrator before continuing" unless current_user.admin? 
    end
end

I'd appreciate any advice, thanks in advance!