A camp has provision for 9 days for 500 men. At the end of 3 days 100 more men were admitted. How long will the food now last?

A camp has provision for 9 days for 500 men. At the end of 3 days 100 more men were admitted. How long will the food now last?

A. 12 days
B. 5 days
C. 9 days
D. 6 days