1. The problem asks for the slope of the line passing through the points (1,0) and (2,4). 2. The formula for slope $m$ between two points $(x_1,y_1)$ and $(x_2,y_2)$ is: $$m=\frac{y_2 - y_1}{x_2 - x_1}$$ 3. Substitute the given points into the formula: $$m=\frac{4 - 0}{2 - 1}$$ 4. Simplify the numerator and denominator: $$m=\frac{4}{1}$$ 5. Since dividing by 1 does not change the value, we can write: $$m=\frac{\cancel{4}}{\cancel{1}}=4$$ 6. Therefore, the slope of the line is 4. 7. The correct answer is D. 4.