Answer:
Options (1), (3) and (7)
Explanation:
Characteristics of the given graph are as followed.
1). For every input value (x-value) there is a different output values (y-values).
So the points on the graph represent a function.
2). Coordinates of all the points are distinct and separate (not in fractions or decimals).
Function given is a discrete function.
3). For every increase in the x-values of the points there is a decrease in y-values.
Therefore, given function is a decreasing function.
Therefore, Options (1), (3) and (7) are the correct options.