(The graph measures level of activity on the horizontal axis and total benefit and cost in dollars on the vertical axis. Total benefit starts at the origin and increases at a decreasing rate until an activity level of 500, after which it decreases. Total cost starts at the origin and increases at an increasing rate. Total benefit exceeds total cost by $1000 at an activity level of 100; total benefit is $1500 and total cost is $500. Total benefit exceeds total cost by about $1250 at an activity level of 200; total benefit is $2500 and total cost is $1250. The gap between total benefit and total cost shrinks after an activity level of 200. Total benefit and total cost intersect at around $3750 at an activity level of 350.) At an activity level of 100