Which of the following sets of molecules will have a zero dipole moment?

Select the incorrect statement from the following.

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $NH_3$ and $NF_3$ molecules have a pyramidal shape with a lone pair of electrons on the nitrogen atom. The resultant dipole moment of $NH_3$ is greater than that of $NF_3$.
Reason $R$: In $NH_3$,the orbital dipole due to the lone pair is in the same direction as the resultant dipole moment of the $N-H$ bonds. $F$ is the most electronegative element.

If $B-Cl$ bond has a dipole moment,explain why $BCl_3$ molecule has zero dipole moment.

Which out of $NH_{3}$ and $NF_{3}$ has a higher dipole moment and why?

The electronegativity difference between $N$ and $F$ is greater than that between $N$ and $H$,yet the dipole moment of $NH_3$ $(1.5 \ D)$ is larger than that of $NF_3$ $(0.2 \ D)$. This is because