The Polynomial Function $I ( t ) = - 0.1 t ^ { 2 } + 1.9$

Multiple Choice

The polynomial function $I ( t ) = - 0.1 t ^ { 2 } + 1.9$ t represents the yearly income (or loss) from a real estate investment, where t is time in years. After what year does income begin to decline?

A) 19 yr
B) 9.5 yr
C) 8.5 yr
D) 12.67 yr