Answer:
Option B is correct
$0.25 does the cost of milk increase every year
Explanation:
Slope-intercept form is given by:
.....[1]
where, m is the rate and b is the initial value
Given the function:

where,
y represents the cost of a gallon of milk.
and
x represents the number of years.
We have to find how much does the cost of milk increase every year.
On comparing given function with [1] we have;
m = 0.25 and b = 3.5
Initially cost of milk = $3.5
and
cost of milk increase every year = $0.25
Therefore, $0.25 does the cost of milk increase every year