Question

My parents are making cakes in the kitchen 用where回答

Answer 1

Where are your parents ?
My parents are making cakes in the kitchen. （提问者应该不知“你父母”在干什么，如果知道也应该得出在厨房的结论，所以直接问在哪。）
若非要死板的回答：
Where are your parents making cakes?
My parents are making cakes in the kitchen. (In the kitchen)

Answer 2

the kitchen ，where My parents are making cakes

Answer 3

Where are your parents making cakes?

Answer 4

where My parents are making cakes is the kitchen