In an AC generator, a coil with $N$ turns, all of the same area $A$ and total resistance $R$, rotates with frequency $\omega$ in a magnetic field $B$. The maximum value of emf generated in the coil is:

1. A
   $NAB\omega$
2. B
   $NABR\omega$
3. C
   $NAB$
4. D
   $NABR$