Answer:
Option D is correct.
Step-by-step explanation:
This is a parallelism problem. Parallelism is the state of being parallel or of corresponding in some way.
Now, let us take option A which is ''that of others''. Option A is wrong because it is 'singular' whereas we are considering 'plural'.
Taking option B which is ''the other''. Option B is wrong because "other" refers to another genetic composition. The words ''each other" refers to interaction between exactly two things or people.
Taking option C which is "another'' is the same as Option B. The word "another" is used for another of an indefinite number of things.
Taking option E: option E is ''that of the next"; it is also singular.