Correct Answer - b
Both asertion and reason are true but reason is not the correct explanation of assertion
`[epsilon_(0)] = [M^(-1) L^(-3)T^(4)I^(2)] , [mu_(0)] = [MLT^(-2)I^(-2)]`
`rArr (1)/(sqrt((mu_(0)// 4 pi ) xx 4 pi epsilon_(0)))= sqrt(( 9 xx 10^(9))/(10^(-7))`
`= sqrt(9 xx 10^(16))`
`= 3 xx 10^(8)m//s`
Therefore `(1)/(sqrt(mu_(0)epsi_(0)))` has dimension of velocity and numerically equal of light.