Correct Option: D

Parallel downloading is very beneficial to performance. Opera 10 provides the maximum parallel connections per host i.e. 8, Chrome 1 and 2, Chrome 4 to 23 gives 6 maximum parallel connections per host, Safari 3 and 4 gives 4 maximum parallel connections per host, Firefox 3, Firefox 4 to 17 gives 6 maximum parallel connections per host.