As a manager, I was responsible for a 50%increase in sales over a three-month period.

A、作为经理，我曾负责的销售额在三个月内增长了50%。
B、作为经理，我负责将销售额在三个月后增长到50%。
C、作为经理，我有责任将销售额在三个月之间提高50%。