Ruby best practices should you use if, case or hash to make conversion methods

All options are valid but which has the best performance, or is the preferred style?

hash

  def codify(pet)
    hash = {
      'dog' => 'D',
      'cat' => 'C',
      'bird' => 'B',
    }
    return hash[pet] || 'U'
  end 

inline

  def codify(pet)
    return 'D' if pet == 'dog'
    return 'C' if pet == 'cat'
    return 'B' if pet == 'bird'
    return 'U'
  end

if else

  def codify(pet)
    if pet == 'dog'
      return 'D'
    elsif pet == 'cat'
      return 'C'
    elsif pet == 'bird'
      return 'B'
    else
      return 'U'
    end
  end

case

  def codify(pet)
    case pet
    when 'dog'
      return 'D'
    when 'cat'
      return 'C'
    when 'bird'
      return 'B'
    else
      return 'U'
    end
  end

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