Question

What is Neptune’s largest moon?

Answer 1

Proteus

Explanation:

Of the 14 known moons of Neptune, Proteus is by far the largest. More details and good graphics here:
https://www.space.com/22222-neptunes-moons.html

Infographic here:
https://www.space.com/21977-neptune-moons-planet-facts-infographic.html