If a and b are even numbers, which of the following CANNOT be the value of a-b?  Choose the correct choice:	A) 10	B) 14	C) 21	D) 24	E) 26
21 is an odd number and the subtraction of two even number should be an even number..   ans 21
<result>C</result>
If a and b are even numbers, which of the following CANNOT be the value of a-b?