The correct answer is:
True.
Explanation:
A sinusoidal function is based on the sine function, or sine wave.
The sine wave repeats based on its period. The period of the sine function is 2π, or 360°. Depending on the transformations applied to the function, the period of the transformed function may be different, but will always be based around this idea of repeating every 2π radians.
Since 2π = 360°, this corresponds with a circle. This means the graph repeats based on positions of a point that move around a circle.