Answer:
b.linear
Explanation:
we know that
The linear equation in slope intercept form is given by

where
y is the total amount spent
x is the number of activities
m is the slope or unit rate
b is the y-intercept or initial value
In this problem we have that
The slope or unit rate of the situation is equal to
The y-intercept or initial value is equal to

substitute the given value
The equation that represent this problem is

therefore
The situation can be modeled with a linear function