2, 2-dimethylpropane
2-methylbutane
2-methylpropane
2, 2-dimethylbutane
The IUPAC name of neopentane is 2,2-dimethylpropane. Neopentane has 5 carbon atoms in total. 4 Carbon atoms are attached to 1 atom. Thus, the longest chain has 3 C atoms, where the second atom has 2 methyl groups. Hence, the correct option is B