单选题 If n=p2 and p is a prime number greater than 5,what is the units digit of n2?
【正确答案】 A
【答案解析】First, all prime numbers greater than 5 are odd numbers with units digit 1,3, 7, or 9. Note that no prime number greater than 5 has units digit 5. The following table summarizes the results for the possible cases.