You only need to use your sense of triangles to choose the correct answer:
x < y < 6
This relation fits only one answer choice:
x = 3, y = 3√3
_____
<em>Additional comment</em>
For multiple choice questions, it isn't always about working the problem. Usually, it is about knowing what the answer has to look like. The usual criteria are (a) is the answer true; (b) does the answer make sense in the context of the problem statement; (c) can you get this answer if you work the problem in detail. More often than not, the first two criteria will let you choose the correct answer without doing any detailed solving.
