ねんのため問題の原文もしるしておきます

原文
For every even positive integer n, the function h(n) is
defined to be the product of all the even integers from 2 to n,
inclusive.
if p is the smallest prime factor of h(100)+1 then p is

between 2 and 10
between 10 and 20
between 20 and 30
between 30 and 40
greater than 40