Assertion A: $C{r}^{+2}$ is a stronger reducing agent

Reason R: Oxidation of  $C{r}^{+2}$ to  $C{r}^{+3}$ attains more stable half filled  configuration in $t_{2g}$  level

A is true but R is false

Both A and R are ture and R is not the correct explanation of A

Both A and R are false

Both A and R are true and R is the correct explanation of A