Suppose within your Web browser you click on a link to obtain a Web page. The IP address for the associated URL is not cached in your local host, so a DNS lookup is necessary to obtain the IP address. Suppose time needed for the DNS query is RTT_dns; Further suppose that the Web page associated with the link contains one base html file and 15 reference objects. Let RTT₀ denote the round trip time between the local host and the web server containing the objects. Assuming zero transmission time needed for each object because they are small, how much time elapses from when the client clicks on the link until the client receives the object if

(a) Non-persistent HTTP with no parallel TCP connections?

(b) Non-persistent HTTP with the browser configured for 4 parallel connections?

(c) Persistent HTTP with pipeline (request for all reference objects can be response in one round trip time)?

(d) Persistent HTTP without pipeline (request for each reference object can be response in one round trip time)?