Answer: work overload
Step-by-step explanation:
From the question, we are informed that Jeremy is a business student at ABC University and that he is currently enrolled for 18 credits, mostly of quantitative courses with high workloads.
We are further told that he also works 25 hours a week as a bartender. This shows that Jeremy has many works he's doing and the likely cause of his stress is work overload. He's performing too much tasks.