To find the slope of a line that passes through two given points, we can use the slope formula, which is:
slope = (change in y)/(change in x)
Let's label the first point as (x₁, y₁) = (-1, 3), and the second point as (x₂, y₂) = (1, 4). Then, we can plug in the values into the formula:
slope = (y₂ - y₁)/(x₂ - x₁)
slope = (4 - 3)/(1 - (-1))
slope = 1/2
Therefore, the slope of the line that passes through (-1, 3) and (1, 4) is 1/2, which corresponds to answer choice C.