Read this case study and then answer the question
A tired junior doctor prescribes the incorrect dose of a drug and the pharmacist is too busy to check it. The nurse who gives the drug is not familiar with it and is about to go on a break. She gives the drug without having it checked by a second person and the patient suffers an adverse reaction due to receiving the wrong dose of the drug.
What are/is the causal factors for this error (select all that apply)?