1) is called 3-methyl hexane because we choose the longest possible continuous chain which has 6 carbons and start numbering from the side that gives the branch lowest possible number.
2) is called 2-methyl-2-butene because we have to give the double bond lowest possible number but in this case double bond in position 2 from both sides so we start from the side gives the branch number 2 not 3
3) is called 7-Ethyl-4-decyne because we have to start from the side that gives the triple bond lowest possible number which is 4 and the branch will be at position 7 (note that the name of 10 carbon is incorrectly written in the choices is called decane (as alkane) or decyne when contains triple bond)
4) is called 2,3-Dimethyl pentane because it is 5 carbons (pentane) and we have two branches of the same alkyl (dimethyl) in positions 2 and 3
5) is called 1-Butanol because it contains 4 carbons and has one OH as functional group which take the suffix -ol in position 1 so we said the name as 1-butanol (remember to give the functional group lowest possible number)
6) is called propyl butyl ether because the longest chain is 4 carbons which called butyl and the smallest chain is propyl, it also has another name 1-Propoxy butane <span />
Explanation:
5 I don't know what is the answer if I got it wrong
Melting? not really sure what type of answer they are going for but the substance is going through the melting phase
