Answer:
The correct answer would be the third one; 4y-6y
Explanation:
The first answer, if simplified, the answer would be 10y. Which isn't the answer you are looking for.
The second answer, also has the answer of 10y, which means that isn't the one.
The third answer, when simplified, has the answer of -2y. Which, of course, would be your answer.
The fourth answer, would be -10y.
Therefor, the correct answer would be the third one.
Hope this helps!