As Gillian took medicine that is not in her prescription it will be drug misuse. The correct option is C.
The use of a drug for a purpose that is not coherent with medical or legal regulations is referred to as drug misuse.
As Gillian was having twisted ankle, she asked Ben for the medication he was taking, this is the case of drug misuse.
Thus, the correct option is C.
For more details regarding drug misuse, visit:
https://brainly.com/question/13745375
#SPJ2