Bond length is the average distance between the nuclei of two atoms held by a bond. This represents the internuclear distance corresponding to minimum potential energy for the system.
(i) Multiple bonds are shorter than corresponding single bonds.
(ii) Sometimes single bond distances are somewhat shorter than double of their respective covalent radii because bonds acquire some particle double bond character.

In which of the following cases, the bond between central atom & F show partial double bond character?
A. NF₃
B. CF₄
C. PF₃
D. OF₂