Final answer:
The graph of the function g(x) = x + 3 is a straight line with a positive slope, as the function represents a linear equation.
Step-by-step explanation:
The graph of the function g(x) = x + 3 is described by a linear equation, which is represented as a straight line on a graph. In the function g(x), x is the independent variable and g(x) or y is the dependent variable. According to the general form y = a + bx, where a is the y-intercept and b is the slope of the line, we see that a (y-intercept) is 3 and b (slope) is 1. Therefore, for every increase of 1 on the horizontal axis (x-axis), there is a rise of 1 on the vertical axis (y-axis). Since b is positive, the line slopes upward to the right. Hence, the correct answer to which is the graph of g(x) = x + 3 is b. Straight line, specifically, a straight line with a positive slope.