Answer:
a: handle down; bristles up
Explanation:
because if you do the opposite, you could bend the bristles and ruin them. you shouldnt put the bristles down in water because it could ruin the bristles by making them softer and the bristles wont stay together so itll make it harder to paint. you shouldnt put them in tightly closed containters because of the same reason for when you put the brushes in upside down