How does a mass drive work? A.
It uses the potential of a spacecraft to nudge an NEO out of its current path.
B.
It removes and ejects mass from an NEO, and gives it a little push.
C.
It involves a small rocket thrust; the mass of the NEO provides the momentum to move it further.
D.
It drives a smaller NEO into a collision course with the hazardous NEO.

im not to sure what it is

it is given that trillions of microbes make up to 1% to 3% of the body mass.

let's take average of this percentage: 2%

consider the average mass of the human body as 70 kg.

then, trillions of microbes would have mass  

therefore, 100 trillion micro-organisms would weigh:

this is an approximate value and could change depending on the mass of the human body and percentage of the microbes present in it.

average mass per microorganism =