Please choose from the GIVEN choices and explain.

D has the following obligations: to C1- (1) P10,000 due January 1, 2009, (2) P10,000 clue February 1, 2009, (3) P10,000 due December 1, 2009; to C2- (1)P10,000 due February 1, 2009, (2) P10,000 due March 1, 2009;and a joint obligation to pay P10,000 in favor of C1 and C2 due April 1, 2009. If D pays C1 P20,000 today, to what obligations shall it be apped? 1. To obligation #1 only 2. To obligation #2 only 3. To obligations #1 & #2, pro-rata 4. To all his obligations to C1 except #3