In case of nitrogen, `NCl_(3)` is possible but not `NCl_(5)` while in case of phosphorous, `PCl_(5)` are possible. It is due to
A. availability of vacant d - orbital in P but not in N .
B. LOWER electronegative of P then N.
C. lower tendency of H bond formation in P than N.
D. occurrence of P in solid while N in gaseous state at room temperture .
