The table below displays the private marginal benefit and the private marginal cost for Sam's Flower Farm. Sam's Flower Farm produces wild flowers. Each acre produces $550 worth of flowers per month. Sam's farm also serves as a local attraction for tourists looking to view birds and butterflies increasing the revenues of local businesses by $50 per month (Note: the social marginal cost is the same as the private marginal cost).

Quantity (acres)	MC Private	MB Private
100	$450	$550
200	500	550
300	550	550
400	600	550
500	650	550

What is the socially efficient number of acres for Sam to plant if all costs and benefits are considered?

300 acres

400 acres

200 acres

100 acres

explain