A regular polygon can be constructed with a compass and straightedge if its number of sides is either any power of 2, any product of the five distinct primes 3, 5, 17, 257, and 65537, or the product of any power of 2 and any of the five distinct primes. Which of the following regular polygons is NOT constructable with a compass and straightedge?
A. A 15-sided regular polygon
B. An 18-sided regular polygon
C. A 48-sided regular polygon
D. A 51-sided regular polygon
E. A 60-sided regular polygon
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