The true statement about the Milky Way and Andromeda galaxies is: They both exert a strong gravitational pull on each other.
The Milky Way and Andromeda galaxies are the two largest galaxies in our local group and are actually on a collision course, indicating that they do exert a strong gravitational pull on each other. The other statements are incorrect: both galaxies are spiral galaxies, and Andromeda is actually larger than the Milky Way in terms of total mass.