I need help to a problem regarding FIFO

Consider a set of four processes with estimated execution times of 2, 3, 4, and 5 seconds. Each process has two successive executions separated by an input/output operation cycle. The scheduling of the processes is FIFO. Knowing that the response times after the second execution, relative to moment 0, are 30, 28, 20, and 25 seconds, specify the durations of the input/output operations for two of these processes.

(a) 7 and 13 seconds
(b) 17 and 14 seconds
(c) 5 and 17 seconds
(d) 9 and 15 seconds