Answer:
B
Step-by-step explanation:
No matter what value you multiply a, the fraction will remain unchanged. That is because you can divide an a out from the numerator and the denominator. Thus, doubling a has no affect on the fraction, and in fact, u can simplify it to just bc. Now, if you halve b, it will simply just halve the actual value. When you halve b, you are simply executing (1/2)(b)(c). Therefore, you can rearrange the expression to be (1/2)(bc), which is just halving bc. If you decrease by 1/2, it's the same thing as being half of the value it was before. Therefore, the answer is b.