To find the distance covered by an object moving in a circular path, you need to calculate the arc length. The formula for the arc length \( s \) of a circle is:

\[ s = r \theta \]

where:
- \( r \) is the radius of the circle
- \( \theta \) is the angle in radians

First, convert the angle from degrees to radians:

\[ \theta = \frac{30^\circ \times \pi}{180^\circ} = \frac{\pi}{6} \]

Now, use the formula to find the arc length:

\[ s = r \times \theta \]
\[ s = 21 \times \frac{\pi}{6} \]
\[ s = 21 \times \frac{3.14}{6} \]
\[ s \approx 21 \times 0.523 \]
\[ s \approx 10.98 \]

Rounded to the nearest meter, the distance covered is approximately 11 meters.

So, the correct answer is:

A. 11m