A plane electromagnetic wave travelling in a non magnetic medium is given by E = (9×10⁸NC⁻¹)sin[(9×10⁸rads⁻¹)t−(6m⁻¹)x]
Where x is in metre and t is in second.
The dielectric constant of the medium is:
A. 5
B. 4
C. 3
D. 2