Let a, b, c, and d be positive integers such that \operatorname{gcd}(a, b)=24, \operatorname{gcd}(b, c)=36, \operatorname{gcd}(c, d)=54, and 70<\operatorname{gcd}(d, a)<100. Which of the following must be a divisor of a ?

**Answer Choices**

A. 5

B. 7

C. 11

D. 13

E. 17