When dealing with timeout values in sockets, the connection timeout can be changed independently of the read/write time out. Which function must be used for this purpose?

What is the full form of DNS?

A. Digital Network System

B. Domain Network System

C. Digital Name Systmem

D. Domain Name System

Which one of the following function checks for the existence of DNS records?

A. checkdns()

B. checkdnsr()

C. checkdnsrr()

D. checkdnsa()

Which one of the following function is used to return an array consisting of various DNS resource records pertinent to a specific domain?

A. dns_get_record()

B. dns_record()

C. dnsrr_get_record()

D. dnsrr_record()

Which one of the following function is used to retrieve the MX records for the domain specified by hostname?

A. getmx()

B. retrieve_mx()

C. getmxrr()

D. retrieve_mxrr()