You work in a company which is named Wiikigo Corp. The company uses SQL Server 2008. You are the administrator of the company database. Now you are in charge of a SQL Server 2008 instance. There is a database named DB1 in the instance. At present about 90 GB of data is stored in DB1. You made some rough calculations that every day about 1 GB of data is modified or inserted. You set the recovery model of DB1 to Simple. According to the company requirements, during business hours, data loss of more than 120 minutes worth of transactions is unacceptable. You have to choose a backup strategy which must comply with the following two requirements: Using as little disk space as possible Complying with the company requirements. So what action should you perform to achieve this goal?（）  

A.A full database backup should be performed once daily. During business hour, a transaction log backup should be performed every two hours. 
B.A full database backup should be performed once daily 
C.A full database backup should be performed once daily. During business hours, a differential backup should be performed every two hours 
D.Perform a full database backup should be performed once every week. A differential backup should be performed once daily. During business hours a transaction log backup should be performed every two hours.