The electric field in an electromagnetic wave is given by $$\vec{E} = \hat{i}40\cos\omega(t - z/c)\ NC^{-1}$$. The magnetic field induction of this wave is (in SI unit):

A

$$\vec{B} = \hat{k}\frac{40}{c}\cos\omega(t - z/c)$$

B

$$\vec{B} = \hat{j}40\cos\omega(t - z/c)$$

C

$$\vec{B} = \hat{i}\frac{40}{c}\cos\omega(t - z/c)$$

D

$$\vec{B} = \hat{j}\frac{40}{c}\cos\omega(t - z/c)$$