Rates of Reaction A Level

Hi,
Im not sure on this question...

Three reactants A, B, and C are reacted together. Doubling the
concentration of A increases the rate by a factor of 2. Changing the
concentration of B has no effect on the rate. Halving the
concentration of C decreases the rate to half its original value.

a ) State the orders with respect to A, B, and C.

I think the order for B would be 0 but not sure how to find A and C?

A and B are 1st order as the [A] and [C] are proportional to the rate of reaction.

A and B are 1st order as the [A] and [C] are proportional to the rate of reaction.

Hi,

Wouldn't it be
A and C are 1st Order ?

Then B:
Zero order since changing the concentration doesn't affect the rate?

A and C are 1st order as the [A] and [C] are proportional to the rate of reaction.