Which of the following is equivalent to the expression below? 42^x/6^x

a.48^x
b.7^x
c.36^x
d.7

it will cost dollar $540

the living room is 3 which means if we divide 325/3 then we get $108

therefore if 1part of the living room cost $108 and 3 costed $325

then total 5part of the room will cost 5*108 which gives $540

where is the option given