Which statement(s) about galaxy groups is/are true?
choose one or more:
a. galaxy mergers in groups are not known to have ever happened
b. galaxies in a group are all moving away from each other.
c. interactions between massive and less-massive galaxies affect only the smaller galaxies.
d. tidal streams can result from galaxy interactions.
e. the largest galaxies tend to have satellite galaxies.

Option D and E are True.

Explanation:

Tidal streams can result from galaxies as a result of interaction between the galaxies due to the gravitational force. While the interaction is going on, stars and gas from the outer most part of the galaxies are usually cut off resulting in the formation of 2 tidal tails out of which one trails and the other one preceeds each galaxy.The largest galaxies like our Milky way galaxies tend to have satellite or smaller galaxies which are bound due to gravitational force as a part of the sub group of larger galaxy which itself is a part of the Local group i.e.,  local galaxy cluster

Why the rest of the question?