So, the function is obviously shifted up by 1 so it rules out A and B, and we also see that the period is 4pi rather than 2pi, and using the fact that:
[tex] \frac{2\pi}{b}=4\pi \implies \frac{b}{2\pi}=\frac{1}{4\pi}\implies b=\frac{1}{2} [/tex]
Now that we know our b value, we see that the correct answer would be C.
