C. Populations.
Hope that's right.
They both have a magnetic field
B. Gamma rays
Gamma rays have highest energy
Answer:
Area of the plates of a capacitor, A = 0.208 m²
Explanation:
It is given that,
Charge on the parallel plate capacitor, 
Electric field, E = 3.1 kV/mm = 3100000 V/m
The electric field of a parallel plates capacitor is given by :



A = 0.208 m²
So, the area of the plates of a capacitor is 0.208 m². Hence, this is the required solution.
The answer should be all of the above