Question

The four gas giants are

Answer 1

Jupiter, Saturn, Uranus, and Neptune

Answer 2

D. Jupiter, Saturn, Uranus, and Neptune
All the outer planets are gas giants; the outer planets start with Jupiter because it is after the asteroid belt.

Just remember the saying:
My Very Elegant Mother Just Served Us Nine Pizzas

This corresponds to the order of the planets:
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Pluto