Based upon the results (250ms delay, 0% lost packets), when does TCP slow start end?

a) the interval between 3 and 4 seconds
b) the interval between 13 and 14 seconds
c) the interval between 7 and 9 seconds

Connecting to host 10.0.0.2, port 5201
[ 14] local 10.0.0.1 port 55070 connected to 10.0.0.2 port 5201
[ ID] Interval Transfer Bandwidth Retr Cwnd
[ 14] 0.00-1.00 sec 84.8 KBytes 695 Kbits/sec 1 14.1 KBytes
[ 14] 1.00-2.00 sec 0.00 Bytes 0.00 bits/sec 0 17.0 KBytes
[ 14] 2.00-3.00 sec 0.00 Bytes 0.00 bits/sec 0 28.3 KBytes
[ 14] 3.00-4.00 sec 105 KBytes 857 Kbits/sec 0 56.6 KBytes
[ 14] 4.00-5.00 sec 260 KBytes 2.13 Mbits/sec 0 113 KBytes
[ 14] 5.00-6.00 sec 191 KBytes 1.56 Mbits/sec 0 226 KBytes
[ 14] 6.00-7.00 sec 636 KBytes 5.21 Mbits/sec 0 452 KBytes
[ 14] 7.00-8.00 sec 2.11 MBytes 17.7 Mbits/sec 0 905 KBytes
[ 14] 8.00-9.00 sec 2.49 MBytes 20.9 Mbits/sec 0 1.77 MBytes
[ 14] 9.00-10.00 sec 2.50 MBytes 21.0 Mbits/sec 0 2.90 MBytes
[ 14] 10.00-11.00 sec 2.50 MBytes 21.0 Mbits/sec 0 3.50 MBytes
[ 14] 11.00-12.00 sec 1.25 MBytes 10.5 Mbits/sec 0 3.16 MBytes
[ 14] 12.00-13.00 sec 1.25 MBytes 10.5 Mbits/sec 0 2.82 MBytes
[ 14] 13.00-14.00 sec 1.25 MBytes 10.5 Mbits/sec 0 2.50 MBytes
[ 14] 14.00-15.00 sec 1.25 MBytes 10.5 Mbits/sec 0 2.64 MBytes
[ 14] 15.00-16.00 sec 1.25 MBytes 10.5 Mbits/sec 0 2.78 MBytes
[ 14] 16.00-17.00 sec 1.25 MBytes 10.5 Mbits/sec 0 2.92 MBytes
[ 14] 17.00-18.00 sec 1.25 MBytes 10.5 Mbits/sec 0 3.04 MBytes
[ 14] 18.00-19.00 sec 1.25 MBytes 10.5 Mbits/sec 0 3.15 MBytes
[ 14] 19.00-20.00 sec 0.00 Bytes 0.00 bits/sec 0 3.25 MBytes