A plane electromagnetic wave is propagating along the direction i^+j^2 , with its polarization along the direction k^ . The correct form of the magnetic field of the wave would be (here B0 is an appropriate constant)

Generally  B→=B0.sinwt−kx   in which direction of propagation is x axis.As per question direction of propagation is along i^+j^2  and Direction of polarization (direction of electric field) is k^  Using, relation E^×B^=C^ or B^=C^×E^ ⇒B^=i^+j^2×k^ ⇒B^=i^−j^2