Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): \( \mathrm{NH_3} \) and \( \mathrm{NF_3} \) molecule have pyramidal shape with a lone pair of electrons on nitrogen atom. The resultant dipole moment of \( \mathrm{NH_3} \) is greater than that of \( \mathrm{NF_3} \).
Reason (R): In \( \mathrm{NH_3} \), the orbital dipole due to lone pair is in the same direction as the resultant dipole moment of the \( \mathrm{N-H} \) bonds. \( \mathrm{F} \) is the most electronegative element.
In the light of the above statements, choose the correct answer from the options given below :