Final answer:
The number that completes the system of linear inequalities represented by the graph is OPTION 4: is not defined.
Step-by-step explanation:
The number that completes the system of linear inequalities represented by the graph is OPTION 4: is not defined. To complete the system, we need another inequality or equation to determine the specific value of the number. The given inequality x - 4y ≤ 4 represents a line on a graph, and the solution to the inequality is the area below or on the line. Without another constraint, there is no specific number that can be identified as completing the system. Therefore, the correct answer is OPTION 4: is not defined.