Answer:
It helps microorganisms grow
Step-by-step explanation:
I think this is the correct answer because I tried searching it up and you sterilise the petri dish before adding the agar, I've used agar in petri dishes a year ago and im pretty sure they don't make cells glow or make bacteria appear larger.
if I had to have a second guess I'd go with the first one but considering the fact that bacteria is usually to small to see with the naked eye the last option seems correct