Consider a small conducting coil $($area $0\mathrm{.}1m^2,$ with $N=100$ turns$)$ which lies flat in the plane of this page. The coil is connected to a $50$ resistor, as shown. There is a strong magnetic field $B=0\mathrm{.}5T$ initially pointing normal to the page $($toward you, in the figure$).$ Over the course of $2$ sec $,$ the field is changed continuously to B $=0\mathrm{.}1T,$ pointing normal but now into the loop $($i$.$e$.,$ it has flipped direction and is now pointing directly away from you in the figure.$)$

What is the magnitude of the average induced emf in the coil?

A$)2$ V

B$)3$ V

C$)4$ V

D$)6$ V

E$)$ None of the above is correct.

The correct answer should be B but I keep calculating A$.$ Please help.