I think either B or C maybe?
A
It was to attract more settlers to the area.
If the root hydro- means "water", then the word that means "an electrical instrument used to monitor underwater sounds" is called a hydrophone. A hydrophone is a kind of microphone that is specifically used to detect and record sound waves underwater.
Answer:
You should walk quickly, or even run fast as you can, if you don't want to be late.
