The expression for the first line is
d = 2.5t + 2.2
Since the second line is parallel to the first line at (0, 1), the slope of the first line is equal to the second line.
From the general form f(x) = mc + b where m is the slope, the slope of the given equation is
m = 2.5
Since it passes to d = 1 at t = 0, the equation of the line is
(d – 1) = 2.5 (t – 0)
d = 2.5t +1
therefore the answer is A.