An electromagnetic wave is represented by the electric field E=E0n^sin[ωt+(6y−8z)] . Taking unit vectors in x , y and z directions to be i^,j^,k^ , the direction of propagation s^ is:
a. s^=53i^−4j^
b. s^=5−4k^+3j^
c. s^=(5−3j^+4k^)
d. s^=53j^−3k^