The correct answer is B

Explanation

The graphs of all the given functions are lines, and the equations are all in the form y = (m times x) + b. When a linear equation is in the form y = (m times x) + b, the slope of the graph of the equation is m , the coefficient of x. The graph of the function f is a line with slope 2, so the only choice that could be the equation of f is function f of x = (2 times x) + 4.