Hmm... I'm unsure but its either B or D.
Answer:
<h2>1.5 L</h2>
Explanation:
The new volume can be found by using the formula for Boyle's law which is

Since we are finding the new volume

From the question we have

We have the final answer as
<h3>1.5 L</h3>
Hope this helps you
He will most likely find that the sand has sunken to the bottom because the molecules in sand are to powerful to break apart and disslove.