Answer: Third option.
Explanation:
You must keep on mind that:
The coefficients are the numbers that are in front of the variables.
If the pair of like terms must have opposite coefficients, then these numbers must have different signs.
So, the idea is that make that the coefficient of x does not be 1/2 but 3, or the coefficient of y does not be 3/2 but -2.
You can make that x has coefficient 3 if you multiply the first equation by 6, as you can see below:
