Answer:
4th option
Explanation:
note that y = f(x)
locate f(x) = 1 ( output) on the y- axis, then a horizontal line passing through y = 1 intersects with the curve at (- 7, 1 ) and (2, 1 )
the input is then the x- coordinates of these 2 points , that is
x = - 7 and x = 2