Hi!
I believe that there were the following options in this question:
A) Which color bends the most to make a rainbow?
B) What color of scented marker has the best smell?
C) Which flower has the prettiest shade of purple on its petals?
D) What is the best-looking color on a high-performance sports car
Now, options b), c) and d) are about a personal preference and opinion - they are not scientific uqestions.
The correct answer is a) - it asks about the properties of light.