以下对集合的操作结果错误的是哪一个选项？（)a = {1, 2, 3, 4}b = {2, 3, 5, 6}

A.＞＞＞ a.intersection(b) == a & b True

B.＞＞＞a.issubset(b) True

C.＞＞＞ a.difference(b) == a - b True

D.＞＞＞ a.union(b) == a | b True