Which of the following is the energy of motion?
a gravitational
b potential
c kinetic
d radiant

Kinetic energy is the energy of the motion.

This is because the kinetic energy can be calculated by using the formula,

K.E.=1/2 mv^2

where, v is the velocity of moving body i.e. the body is in motion.

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 =