Step 1: Recall the formula for the midpoint.
The midpoint of a line segment joining two points \( (x_1, y_1) \) and \( (x_2, y_2) \) is given by:
\[ \text{Midpoint} = \left( \frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2} \right). \]
Step 2: Substitute the coordinates of the given points.
The given points are \( (4, 5) \) and \( (-2, -1) \). Substituting into the formula:
\[ \text{Midpoint} = \left( \frac{4 + (-2)}{2}, \frac{5 + (-1)}{2} \right). \]
Step 3: Simplify the calculations.
\[ \text{Midpoint} = \left( \frac{4 - 2}{2}, \frac{5 - 1}{2} \right) = \left( \frac{2}{2}, \frac{4}{2} \right) = (1, 2). \]
Final Answer: The midpoint is \( \mathbf{(1, 2)} \), which corresponds to option \( \mathbf{(3)} \).