Ans: C
Consider $y=a\sin(x^\circ+\theta)$.
Consider $y=a\sin(x^\circ+\theta)$.
If $\theta$ is positive, the graph translates to the left $\theta$ units. If $\theta$ is negative, the graph translates to the right $-\theta$ units.
Note that the maximum point $(90, 1)$ is translate to $(135,2)$.
Therefore, $\theta=-45^\circ$.
If $a$ is positive, the graph enlarges $a$ times along the $y$-axis. If $a$ is negative, the graph enlarges $a$ times along the $y$-axis and then reflects with respect to the $x$-axis.
Note that the maximum value $1$ is enlarged to $2$. Therefore, $a=2$.
