pick from the following.
a). To pay them..
b). To help them..
c). To thank them..
d). To make them work harder..
Given those answer options, answer the question: Read the following article and answer the question. Article: Except for a few times, Americans are not big present-givers. There's no exchange of presents among business people, and if one American tries to give another a present, it may look like that he wants to bribe him. Americans have learned that in some other countries people like to give presents to others, but among ourselves we don't see the need for presents. Even friends may never exchange presents. When I go to foreign countries, I try to bring back little things for _ but nobody would feel unhappy if I didn't. I don't often remember a friend's birthday, and few people outside of my family remember mine. If someone gave me presents too often, I'd get unpleasant. But a present from a foreigner - that kind from his or her homeland -- won't go wrong, except to government employees who can't be given presents. You usually open a present at once and in front of the person who gives it except Christmas and birthday presents. You should only say, "It's so nice. Thanks..." when you get Christmas or birthday presents. You may want to bring a bottle of wine or flowers to a dinner party, but you're never asked to. Nobody will mind if you bring wine, but your friend may not use it that evening. At Christmas we often give presents to our family and sometimes our friends. We also give presents to people who have been helpful during the year- doormen, babysitters, housecleaners, newspaper senders-- anyone who has often helped us. Question: Why do Americans also give presents to housecleaners at Christmas? Answer:
A:
c).