The graph of y = f(x) is shown in the xy-plane. What is the value of f(0) ? A) 0 B) 2 C) 3 D) 4

Explanation:
When we want to know the value of f(0) or f(-1) or f(5), it means that we want to find out the value of the function when x = 0 - or x = -1 or x = 5.
In this case we want to know the value of y when x = 0.
In the figure it is shown that the graph crosses the y-axis at y = 4.
When a graph crosses the y-axis is when x = 0 (always), so f(0) = 4
Answer:
The answer is option D) 4