Consider the linear equation $y = b_0 + b_1 x$.

a. In the equation, $b_0$ is

A. the dependent variable
B. the independent variable
C. the slope
D. the $y$-intercept

b. In the equation, $b_1$ is

A. the slope
B. the dependent variable
C. the $y$-intercept
D. the independent variable

c. Give the geometric interpretation of $b_0$. It indicates

A. how much the $y$-value on the straight line changes when the $x$-value increases by unit
B. how much the $x$-value on the straight line changes when the $y$-value increases by unit
C. the $y$-value where the straight-line graph of the linear equation intersects the $y$-axis
D. the $x$-value where the straight-line graph of the linear equation intersects the $x$-axis

d. Give the geometric interpretation of $b_1$. It indicates

A. the $y$-value where the straight-line graph of the linear equation intersects the $y$-axis
B. how much the $y$-value on the straight line changes when the $x$-value increases by unit
C. how much the $x$-value on the straight line changes when the $y$-value increases by unit
D. the $x$-value where the straight-line graph of the linear equation intersects the $x$-axis