Boolean statement C#

I'm new to coding (3 weeks) and I am completely stumped on how do this assignment. We have to write a code that asks the user to input name, age, height, weight, and gender. Then the code has to calculate the user's Basal Metabolic Rate base on the user's gender. I have everything up until the point where the if/else statement begins, after thats is where I'm completely lost. Any help would be appreciated.