The constraints are:
\[
x \geq 0, \quad y \geq 0, \quad x + y \geq 4.
\]
1. Interpretation of Constraints:
- \( x \geq 0 \): The region lies to the right of the \( y \)-axis.
- \( y \geq 0 \): The region lies above the \( x \)-axis.
- \( x + y \geq 4 \): The region is above or on the line \( x + y = 4 \).
2. Feasible Region:
The feasible region is determined by the intersection of these constraints in the first quadrant. The line \( x + y = 4 \) intersects the axes at:
- \( x = 4, y = 0 \) (on the \( x \)-axis),
- \( x = 0, y = 4 \) (on the \( y \)-axis).
Since \( x \geq 0 \) and \( y \geq 0 \), these points form the boundary of the feasible region. The feasible region is unbounded but includes two corner points at:
- \( (4, 0) \),
- \( (0, 4) \).
3. Number of Corner Points:
The feasible region has exactly two corner points.
Hence, the correct answer is (C) 2.