The Profit Function for a Product Is Given By $P ( x ) = - 0.7 x ^ { 3 } + 115.5 x ^ { 2 } - 3710 x - 84,000$

Multiple Choice

The profit function for a product is given by $P ( x ) = - 0.7 x ^ { 3 } + 115.5 x ^ { 2 } - 3710 x - 84,000$ dollars, where x is the number of units produced and sold. Determine the levels of production and sale that give break-even.

A) 80 or 100 units
B) 100 units
C) 120 units
D) 90 or 120 units