[求助]求助一道数学JJ

28.The consecutive integer between 1-100 inclusive, while X=n(n+1),what's the

possibility of x in the sequence?

     A)1/4  B) 2/3 C)1/2  D)3/4  E)记不清了
     [cowslip只记得正确的选项了 1/2]

怎么没有人回答啊！！！NN们帮帮忙吧，快要考了。