Final answer:
When approaching Pierre Regional airport from the southwest with winds reported from 240 at 12 knots, the most suitable runway and traffic pattern entry would be runway 24, approaching from the northeast and making a standard left traffic pattern entry.
Step-by-step explanation:
When approaching Pierre Regional airport from the southwest with winds reported from 240 at 12 knots, you need to consider the wind direction to determine the appropriate runway and traffic pattern entry. In this case, the wind is blowing from the southwest. The most suitable runway and traffic pattern entry would be a runway that aligns with the wind direction, which is runway 24. This means you would approach the runway from the northeast and make a standard left traffic pattern entry.