ICMP (a) is required to solve the NAT traversal problem
(b) is used in Traceroute
(c) has a new version for IPv6
(d) is used by Ping

(b) is used in Traceroute

(d) is used by Ping

Explanation:

ICMP is the short form of Internet Control Message Protocol. It is a protocol used by networking devices such as routers to perform network diagnostics and management. Since it is a messaging protocol, it is used for sending network error messages and operations information. A typical message could be;

i. Requested service is not available

ii. Host could not be reached

ICMP does not use ports. Rather it uses types and codes. Some of the most common types are echo request and echo reply.

Traceroute - which is a diagnostic tool - uses some messages available in ICMP (such as Time Exceeded) to trace a network route.

Ping - which is an administrative tool for identifying whether a host is reachable or not - also uses ICMP. The ping sends ICMP echo request packets to the host and then waits for an ICMP echo reply from the host.

ICMP is not required to solve NAT traversal problem neither does it have a new version in IPV6.

a  social news website  is an  internet  website  that features  user-posted stories. such stories are ranked based on popularity, as voted on by other users of the site or by website administrators. users typically comment online on the news posts and these comments may also be ranked in popularity. since their emergence with the birth of  web 2.0, social news sites have been used to link many types of information, including news, humor, support, and discussion. all such websites allow the users to submit content and each site differs in how the content is moderated. on the  slashdot  and  fark  websites,  administrators  decide which articles are selected for the front page. on  reddit  and  digg, the articles that get the most votes from the community of users will make it to the front page. many social news websites also feature an online comment system, where users discuss the issues raised in an article. some of these sites have also applied their voting system to the comments, so that the most popular comments are displayed first. some social news websites also have a  social networking  function, in that users can set up a user profile and follow other users' online activity on the website.