which of the following product of e, h, μ, G (where p is the permeability) be taken so that the dimensions of the product are same as that of the speed of light?

Here v=eahbμcGd. Taking the dimensions,  M0LT−1A0=AT1aML2T−1bMLT−2A−2cM−1L3T−2dM0LT−1A0=Mb+c-dL2b+c+3dTa−b-2c-2dAa-2cb+c-d=0---(1)2b+c+3d=1---(2)a-b-2c-2d=-1---(3)a-2c=0---(4)  Solving for a,b,c and d, we get a=−2,b=1,c=−1,d=0 Thus, v=e−2hμ−1G0