The Cost of Producing $t$ Units Is $C = 3 t ^ { 2 } + 9 t$

Multiple Choice

The cost of producing $t$ units is $C = 3 t ^ { 2 } + 9 t$ , and the revenue generated from sales is $R = 4 t ^ { 2 } + t$ . Determine the number of units to be sold in order to generate a profit.

A) $t > 0$
B) $t > 8$
C) $t > 10$
D) $t > 9$