Final answer:
The best course of action to prevent this problem from happening again would be to develop a system that prevents miscommunication caused by messy handwriting.
Step-by-step explanation:
The best course of action to prevent this problem from happening again would be (C) develop a system that prevents messy handwriting from causing miscommunication that leads to error. This incident occurred due to miscommunication resulting from messy handwriting, which led to the wrong substances being administered to patients. By implementing a system that eliminates the possibility of miscommunication caused by messy handwriting, such incidents can be avoided in the future.