Since the number of pages in the magazine is always a multiple of 32, we can represent the number of pages as 32n, where n is a positive integer.
The front cover is always counted as page 1, so the last page of the magazine would be 32n.
The center spread of the magazine would be comprised of two facing pages, which would be located in the middle of the magazine. Since the number of pages in the magazine is even (since 32 is even), the center spread would have an even number of pages, and the page numbers of the two center pages would be consecutive odd numbers.
Let's consider the options:
a. 15 and 16 - These are not consecutive odd numbers, so they cannot be the page numbers of the two center pages.
b. 30 and 31 - These are consecutive odd numbers, but they do not correspond to a valid number of pages in the magazine (since 32 does not divide either 30 or 31).
c. 50 and 51 - These are consecutive odd numbers, but they do not correspond to a valid number of pages in the magazine (since 32 does not divide either 50 or 51).
d. 96 and 97 - These are consecutive odd numbers, and we can check that they correspond to a valid number of pages in the magazine:
32n = 96 -> n = 3
The magazine would have 32 x 3 = 96 pages, and the two center pages would be numbered 96/2 = 48 and 49.
Therefore, the answer is (d) 96 and 97.