Deadlock and critical section problem


Consider the three processes A, B, C to be scheduled as per SRT algorithm. A is known to be scheduled first and when A has been running for 7 units of time , C has arrived, C has run for 1 unit of time when B has arrived and completed running in 2 units of time, what could be the minimum time of execution for A and C?
a) 11 and 4
b) 11 and 3
c) 12 and 3
d) 12 and 4