Answer:
B) {-21, -7, 7, 21}
Step-by-step explanation:
A: While -21 and 21 are odd and multiples of 7, it's missing the other elements of Set Z that are also odd and multiples of 7.
B: This is correct because -21, -7, 7, and 21 are all odd numbers and multiples of 7.
C: -14 and 14 aren't odd numbers, for they can be divided by 2.
D: Again, this includes the number -14, so these elements aren't completely odd.
Therefore, the answer is B) {-21, -7, 7, 21}.
