The Parametric Equations for the Paths of Two Projectiles Are $t = \frac { \pi } { 2 } ? \text { Round your answer to two decimal }$

Multiple Choice

The parametric equations for the paths of two projectiles are given below. At what rate is the distance between the two objects changing at $t = \frac { \pi } { 2 } ? \text { Round your answer to two decimal }$ places. $\begin{array} { l } x _ { 1 } = 12 \cos 2 t , y _ { 1 } = 6 \sin 2 t \\x _ { 2 } = 6 \cos t , y _ { 2 } = 7 \sin t\end{array}$

A) $0.86$
B) $1.54$
C) $0.58$
D) $- 1.73$
E) $- 0.65$