The hybridisation in both$CH_4$ and $NH_3$ is $sp^3$ .Yet $CH_4$ is tetrahedral and $NH_3$ is of pyramidal shape because

Question

$\begin{array}{1 1}(a)\;\text{Nitrogen is more electronegative than carbon}\\(b)\;NH_3\text{contains three single bonds and one lone pair}\\(c)\;\text{The no of surrounding atoms in }NH_3\text{ is 3}\\(d)\;NH_3\text{ contains three single bonds and no lone pairs}\end{array}$