The correct option is A 10
In the figure, the x-axis represents the time and y-axis represents the number of people.
In a line graph, the value of datum at any point can be found using the line.
The time 2:30 pm is exactly halfway between 2 and 3 pm.
The number of people is on the y-axis corresponding to the point between that at 2 and 3. Halfway between 5 and 15 on a number line is 10.
Hence the number of people at 2:30 pm are 10.