The correct option is A 2
The value of x in KA1(SO4)x⋅12H2O is 2.
K and Al have charges +1 and +3 respectively. Total charge on cations is 1+3=4.
Each sulphate ion has charge of −2. To balance +4 charge on cations with −2 charge on sulphate ions, two sulphate ions are required.
Hence, the option (B) is the correct answer.