Question

this type of galaxy contains very little dust and gas.
elliptical
irregular
spiral
all galaxies

Explanation:

Elliptical galaxies are known to have very little dust and gas compared to spiral or irregular galaxies. Spiral galaxies have more dust and gas for star formation in their arms, irregular galaxies have varying amounts but more than elliptical, and "all galaxies" is incorrect as different types have different compositions.

Answer:

elliptical