Answer: Option (d) is the correct answer.
Explanation:
Rate law is the rate which is in equilibrium with the concentration of reactants raised to the power of their coefficients.
For example, 
Rate, r = k
........ (1)
So, when concentration of A is doubled then rate of reaction also doubles. Hence, then rate law will be as follows.
2r = k
......... (2)
Dividing equation (1) by (2) we get the following.
= ![\frac{k[A]^{x} \times [B]^{y}}{k[2A]^{x} \times [B]^{y}}](https://tex.z-dn.net/?f=%5Cfrac%7Bk%5BA%5D%5E%7Bx%7D%20%5Ctimes%20%5BB%5D%5E%7By%7D%7D%7Bk%5B2A%5D%5E%7Bx%7D%20%5Ctimes%20%5BB%5D%5E%7By%7D%7D)
Therefore, cancelling common factors we get the following.

= 2
x = 1
Thus, we can conclude that in the reaction A + B C, doubling the concentration of A doubles the reaction rate and doubling the concentration of B does not affect the reaction rate then rate of reaction will be as follows.
rate = k[A]