The correct order of stability of isomers of pentanes is

The correct order of stability of isomers of pentanes is ${\mathrm{CH}}_3{\left({\mathrm{CH}}_2\right)}_3{\mathrm{CH}}_3<{\left({\mathrm{CH}}_3\right)}_2{\mathrm{CHCH}}_2{\mathrm{CH}}_3<{\left({\mathrm{CH}}_3\right)}_4\mathrm{C}$

As branching grows, stability often rises as well.
The order of stability is as follows: ${\mathrm{CH}}_3{\left({\mathrm{CH}}_2\right)}_3{\mathrm{CH}}_3<{\left({\mathrm{CH}}_3\right)}_2{\mathrm{CHCH}}_2{\mathrm{CH}}_3<{\left({\mathrm{CH}}_3\right)}_4\mathrm{C}$

Hence, option D is correct.