To complete your pictorial representation of the problem, you should compile two lists: one of known quantities and one listing the unknown quantities that will allow you to answer the question in the problem. below are all of the relevant quantities in this problem: the initial and final velocities of the puck (vx)i and (vx)f, the magnitude jx of the impulse delivered by the stick, and the mass m of the puck. sort them accordingly.

i think its c if i'm wrong

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 =