The molecular mass of two hydrocarbons $\mathrm{A}$ and $\mathrm{B}$ are $16 \mathrm{u}$ and $44 \mathrm{u}$ respectively. Do they belong to the same homologous series?

Select the hydrocarbons which are members of the same homologous series.

${\mathrm{C}}_5{\mathrm{H}}_{10}, {\mathrm{C}}_7{\mathrm{H}}_{12}, {\mathrm{C}}_6{\mathrm{H}}_{10}, {\mathrm{C}}_3{\mathrm{H}}_8, {\mathrm{C}}_4{\mathrm{H}}_{10}, {\mathrm{C}}_7{\mathrm{H}}_{16}$

Out of the given hydrocarbons, which one undergoes substitution reaction?

${\mathrm{C}}_4{\mathrm{H}}_8, {\mathrm{C}}_5{\mathrm{H}}_{12}, {\mathrm{C}}_6{\mathrm{H}}_{10}, {\mathrm{C}}_3{\mathrm{H}}_6$