JAMB 1989 · UME · Q3

Divide by primes: $2520 = 2^3 \times 315$, and $315 = 3^2 \times 35$

So $2520 = 2^3 \times 3^2 \times 5 \times 7$, and the prime factors are 2, 3, 5 and 7, option C.