C. 1/3
This is because you would first distribute the 4/3 to each term in that equation. Since taking the 4th root is the same as raising it to the 1/4, you multiply 1/4*4/3, which results in 1/3. At that point you have (p^1/3)/(q^1/3) on the left and (p^x)/(q^x) on the right. Therefore, x must equal 1/3