Final answer:
The volume of a prism with a base area of 3 m² and a height of 12 m is 36 m³ (option a).
Step-by-step explanation:
To calculate the volume of a prism, multiply the base area by the height of the prism. For a prism with a base area of 3 m² and a height of 12 m, the volume can be calculated as follows:
V = base area × height
V = 3 m² × 12 m
V = 36 m³
Therefore, the volume of the prism is 36 m³, which corresponds to option (a).