Suppose U={1,2,3,4,5,6,7,8,9,10} is the universal set, and P={1,4,9}. What is P'?
A. {2,3,5,6,7,8}
B. {2,4,6,8}
C. {1,2,3,4,5,6,7,8,9,10}
D. {2,3,5,6,7,8,10}