单选题 ________ he was an old customer, the boss allowed 5% discount off the prices of the goods.
A. Gave B. To give that
C. Given that D. Giving that

【正确答案】 C
【答案解析】[考点] 固定句型
[解析] given that可以理解为considering，意为“考虑到”。根据题意，故选C。