有题不懂求解

meau

for every positive even integer n, the function h(n) is defined to be the product of all 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
bigger than 40

大糖葫芦

应该是大于40那个选项吧
依题得h(100)=2*4*.....*96*98*100=2^50*(1*2*....*47*48*49*50)
所以h(100) 包含了小于50的所有质数，最大的就是47了
因为相邻的两个自然数除了1没有公约数，h(100)+1和h(100)除1外无公约数
p是大于47的质数