Final answer:
The number of first aid units required for a 43-passenger bus depends on regulations and guidelines, but a general guideline is to have at least one first aid kit on board. Assuming one first aid kit is sufficient, the answer is A. 16.
Step-by-step explanation:
The number of first aid units required for a 43-passenger bus depends on the regulations and guidelines set by authorities. However, a general guideline is to have at least one first aid kit on board.
If we assume that one first aid kit is sufficient, then the answer would be A. 16. This is because first aid kits typically contain multiple units, such as bandages, antiseptics, and other medical supplies.