The distance-time graph above, shows the position of an object at different times. Calculate the speed of the object as it moves from A to B.

Question

$\begin{array}{1 1} (a)\;1 \;m/s\\ (b)\;2 \;m/s\\ (c)\;2.5\;m/s \\ (d)\; 1.5 \;m/s \end{array}$