有效地处理顾客的问题可以使其成为一名更加忠实的顾客。
选项：

A:Dealing effective with a customer who has a problem can make him/her into a more loyal customer.
B:Dealing efficient with a customer who has a problem can make him/her into a more loyal customer.
C:Dealing effectively with a customer who has a problem can make him/her into a more loyal customer.
D:Dealing efficiency with a customer who has a problem can make him/her into a more loyal customer.