what will effective_start_date set to at the end of the snippet below?

If acp_service_start_date is 15-Aug-2005 and calculation_date is l-Aug-2010, what will
effective_start_date set to at the end of the snippet below?

A.
15-Aug-2010

B.
01-Aug-2010

C.
15-Aug-2005

D.
15-Aug-2009