Answer:
A. 
Step-by-step explanation:
We are given that,
The linear regression passes through the points (1,2) and (3,5).
As, the slope of a linear line is given by,
.
We get, the slope of the linear regression is,
Slope =
.
i.e. Slope =
.
i.e. Slope =
.
i.e. Slope = 1.5
As, the linear line is given by 'y=mx+b', where m is the slope and b is the y-intercept.
Substituting the slope and point (1,2) in the general form, we have,
implies
implies
i.e. b= 0.5
Hence, the equation for the regression line is 