Let R = (Z2 × Z2, +,.) forms a ring of module 2 such that (a, b) + (c, d) = (a + c, d + d) and (a, b) (c. d) = (a.c, b.d) for (a, b), (c, d) ∈ Z2 × Z2 then-
1
R is a commutative ring with unity and it contains divisor of zero
2
R is a non commutative ring with unity and it contains divisor of zero
3
R is a commutative ring without unity and it contains no divisor of zero
4
R is a commutative ring with unity and it contains no divisor of zero