When n >; N =5! Unit number of result =1* 2 * 3 * 4 * 5 * ... * n =120 * ... n must be 0.
So 1! +2! +3! +…+ 100! Get this number, and its unit number is 1! +2! +3! +4! decision
1! +2! +3! +4! = 1+2+6+24=33, so choose B.