The Percentage $p ( t )$ Of Children Who Are Able to Speak in at Least

Multiple Choice

The percentage $p ( t )$ of children who are able to speak in at least single words by the age of t months can be approximated by the equation. $$p ( t ) = 100 \left( 1 - \frac { 12,156 } { t ^ { 4.17 } } \right)$$
What percent of children are able to speak in at least single words by the age of 14 months Round to the nearest percent.

A) 67%
B) 80%
C) 55%
D) 73%
E) 20%