Answer:
O1: b) linear, proportional
O2: a) linear, non-proportional
O3: c) nonlinear
Step-by-step explanation:
Recall that a proportional function can be drawn as a straight line (linear function) through the origin (0,0).
O1 is a proportional function since it is linear and goes through the origin.
O2 has a y-intercept of y = 5; therefore, it is not proportional because it does not go through the origin (0,0), although it is linear.
O3 resembles a quadratic function, which means it's not a linear function (nonlinear).
