Answer:
a) open in February because the $4,000 of total revenue exceeds the $3,500 of variable costs.
Explanation:
In the short run, when the demand for a product decreases below break even point, a business should remain in operations as long as the total revenues are equal or larger than variable costs.
In this case Stu will only earn $4,000, which is not enough to make a profit, but will cover all the variable costs. If he remains closed during February, he will still have to pay $1,500 in fixed costs.