Which of the following is faster?

Question

$\begin{array}{1 1} (a)\; \text{a bus covering a distance of 5km in 2 hr} \\ (b)\; \text{a man running a 100 m sprint in 9s} \\ (c)\; \text{a car travelling 2 km in 1 hr} \\ (d)\; \text{a man riding bicycle for 30 minutes covering a distance of 3 km} \end{array}$