Explanation:
(b) x is at 2 twice, and -2 twice.
y is at 2 three times, and -2 three times.
The graph that fits is I.
(c) x is at 2 twice, and -2 twice.
y is at 2 once, and is never negative.
The graph that fits is IV.
(d) x is at 2 and stays there for a period of time.
y is at -2 and stays there for a period of time.
The graph that fits is II.