Final answer:
The Andromeda Galaxy is the one not being "eaten" by the Milky Way. The Sagittarius Dwarf and Canis Majoris Dwarf galaxies are currently being absorbed by the Milky Way.
Step-by-step explanation:
The galaxy that the Milky Way is not currently "eating" or absorbing among the options provided is the Andromeda Galaxy (c). The Sagittarius Dwarf Galaxy (a), the Canis Majoris Dwarf Galaxy (d), and other small satellite galaxies are being accreted by the Milky Way. Specifically, the Sagittarius Dwarf Galaxy is the closest to the Milky Way and is slowly being integrated into our galaxy's bulge and halo, a process that will take another 100 million years or so. The Canis Major Dwarf Galaxy has had long tidal tails stripped from it and is expected to merge with the Milky Way over about the next billion years. Meanwhile, the Andromeda Galaxy is not being absorbed by the Milky Way; instead, it is on a collision course with our galaxy, but this event won't happen for another 4 billion years.