Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: cyanide and phosphorus trifluoride ligands stabilize metals in low oxidation states.
Reason R: Cyanide and phosphorus trifluoride ligands are excellent π-acceptor ligands.
In the light of the above statements, choose the most appropriate answer from the options given below: