Answer:
B. What must be given up to acquire it
Step-by-step explanation:
The opportunity cost is the cost which is to be sacrificed to gain for some better option
Since in the given case the aunt is thinking to open a hardware store but it will cost her $500,000 for rent and the to purchase the stock
And, also she also have to quit her accountant job for $50,000
So in this option quitting the job is to be considered as an opportunity cost