verb
respond
rih-SPAHND/rɪˈspɑːnd/
Reply or react to something.
The resident responds to the neighbor waiting at the door.

Etymology
“Back” and “pledge” combine in the Latin sense “promise in return.” The same verb also meant “answer,” connecting a reciprocal assurance with the broader act of replying.
In context
you filed the complaint and the defendant in California has 30 days to respond so one of the ways that a defendant could respond is by filing an answer basically saying I deny deny deny deny deny
More examples
- Please respond to my email by Friday.
- The audience responded with laughter.
- His infection is responding well to treatment.
Forms
respond · responds · responded · responding
response noun — An answer or a reaction.
responsive adjective — Quick to answer or react.