A current of 5.0 A flows for 4.0 h through an electrolytic cell containing a molten salt of metal M. This results in deposition of 0.25 mol of the metal M at the cathode. The oxidation state of M in the molten salt is (1 Faraday = $$96485 \text{ C mol}^{-1}$$)

A

+1

B

+2

C

+3

D

+4