Which of the following pairs of compounds do not exist?

Identify the correct statement.

Assertion $(A):$ $VF_5$ is stable while $VCl_5$ is not.
Reason $(R):$ Fluorine stabilizes the higher oxidation state due to its higher bond enthalpy.
The correct option among the following is

On adding $KI$ to a solution of copper sulphate,what happens?

Identify the statements which are not correct.
$i$. $CrO_3$ and $Mn_2O_7$ are basic oxides
$ii$. $V_2O_3$ and $V_2O_4$ are acidic oxides
$iii$. $Cr(VI)$ is more stable than $W(VI)$

Among the following,which is the strongest oxidizing agent?