The correct option is C Neopentane
Neopentane, also called 2,2-dimethylpropane, is a doubly branched chain alkane with five carbon atoms with formula;CH3−C(CH3)2−CH3. In neopentane all the H atoms are same (1o).
Thus it gives only one mono chloroalkane on chlorination.
Hence, the correct answer is option (c).