The correct option is C divergence free and irrorational
Vector field, →F=x^i−y^j
(i) Divergence of the field
▽.→F=∂∂x(x)+∂∂y(−y)=1−1=0
∴→F is divergence free.
(ii)▽×→F=∣∣
∣
∣
∣∣^i^j^k∂∂x∂∂y∂∂zx−y0∣∣
∣
∣
∣∣
=^i(0)−^j(0)+^k(0)=→0
∴→F is an irrotatioanl field.