When the employer receives an osha citation, it must be:

When you receive an OSHA Notice, you must post it (or a copy of it) at or near the place where each violation occurred to make employees aware of the hazards to which they may be exposed. 

When you receive an OSHA Notice, you must post it (or a copy of it) at or near the place where each violation occurred to make employees aware of the hazards to which they may be exposed. The OSHA Notice must remain posted for 3 working days or until the hazard is abated, whichever is longer.

Answer d would be the best answer, for he wants to have part in biotechnology. an ekg technician is quite similar.