Answer: C) 6
Step-by-step explanation:
The function is somewhat sinusoidal but not entirely. Its composed of piecewise line segments when we should have a single continuous smooth curve; however, it's still periodic since it repeats itself.
Let's start at the top at the left most corner. This point has x coordinate of x = 1.
The other endpoint of this top left flat portion is when x = 2. Then the function curve goes downhill until it reaches x = 4. From x = 4 to x = 5, we're at the flat bottom part. From x = 5 to x = 7 is when the function increases.
Once we get to x = 7, the process described earlier starts all over again. So this is when the cycle ends and the length of the period is 7-1 = 6 units. The function repeats itself every 6 units, or you can say the length of each cycle is 6 time units (eg: 6 seconds).