Question

you have been injured in the laboratory (cut, burn, etc.). first you should
visit the school nurse after class
see a doctor after school
tell the science instructor at once
apply first aid yourself

Explanation:

In a lab injury situation, immediate action to inform the science instructor (who can provide guidance or arrange proper care) is crucial. Delaying (like after class/school) or self - first - aid (without proper knowledge) is unwise.

Answer:

C. tell the science instructor at once