Answer:
D.
Step-by-step explanation:
The last option, option D is not linear.
In mathematics, linear refer to a proportional behaviour that can be modelled with a line, the functions that model this behaviour are called linear functions, and their graphs are lines.
Now, specifically, in Algebra, a linear expression refers to an expression which has variables with an exponent equal to 1, like option A, B and V. As you can see option D has an expression which variable is squared, that means it's not linear, and its graph is not a line, but a parabola.
