The general equation is y = a sin(b[x+c]) + d, where a is the amplitude, b is the frequency, and d is the midline.
For the first equation, only one choice has a midline y = 4, which is h(x).
For the second equation, the first and fifth choices have midline y = 8, but the frequency of 2 only fits the fifth choice: q(x).
For the third equation, the midline of y = 1 only fits g(x).
The fourth equation has midline y = 2 and frequency of 4, which only fits the last choice, r(x).
