To find the average speed of an object, you can use the formula:
\[ \text{Average Speed} = \frac{\text{Total Distance}}{\text{Total Time}} \]
In this case, the object moves a distance of 10 meters in 5 seconds. Plugging in the values:
\[ \text{Average Speed} = \frac{10 \text{ meters}}{5 \text{ seconds}} = 2.0 \text{ m/s} \]
Therefore, the average speed of the object is 2.0 m/s.
The correct answer is: a. 2.0 m/s.