Please help me I give to best answer

B? i feel like this is a trick  

I'm pretty sure the answer is alcohol 

Bromine has atomic number  35  which means there are  35 protons  and  44  neutrons to give a total of 79 nucleons. the fact that it's a positive ion means that it has lost an electron; so there'll be  34 electrons. 

Melting increases as mass increases. since alkanes are not branched molecular structures, the one with the heavier mass will have higher melting point.  octane's mp > butane's mp