SE Strategy

The researcher noted that microbes, although _____, make up far more of the living protoplasm on Earth than all humans, animals and plants combined.

An invisible

B omnipresent

C dimunitive

D ubiquitous

E minuscule

F ethereal

The answers for the above question are A,F. Can someone explain how to arrive at such a conclusion?

Where’s the question from? And please share your logic