Percolating is the process of a liquid slowly passing through a filter.
Answer:
D Growing a garden is like putting money in the bank
"slow and steady wins the race."
The technique that this sentence best illustrates is understatement.
Understatement means that you are not showing the full 'strength' of something, but it is rather understated - so here, the coach only said that 'he was glad' even though his team won the Super Bowl, which is a huge deal. So his emotions should have been way stronger.