B.) A group of cells working together. If it were D.), the question would have had to be A cell is made up of...
G=?
m=7.35*10^22kg
r=1.74*10^6m
G=6.67*10^-11nm^2kg^-2
you can use the formula
g=Gm/r^2
Explanation:
It is given that,
Area of nickel wire, 
Resistance of the wire, R = 2.4 ohms
Initial value of magnetic field, 
Final magnetic field, 
Time, t = 1.12 s
Let I is the induced current in the loop of wire over this time. Te emf induced in the wire is given by Faraday's law as :






Induced current in the loop of wire is given by :



So, the induced current in the loop of wire over this time is
. Hence, this is the required solution.