An emf of 25.0 mV is induced in a 500-turn coil when the current is changing is at the rate of 10.0A/s. What is the magnetic flux through each turn of the coil at an instant when the current is 4.0A?
A. `20muT.m^2`
B. `10muT.m^2`
C. `15muT.m^2`
D. `30muT.m^2`