Write an Equation for the Hyperbola $\frac { x ^ { 2 } } { 23 } - \frac { y ^ { 2 } } { 16 } = 1$

Multiple Choice

Write an equation for the hyperbola.
-A comet follows the hyperbolic path described by $\frac { x ^ { 2 } } { 23 } - \frac { y ^ { 2 } } { 16 } = 1$ , where $x$ and $y$ are in millions of miles. If the sun is the focus of the path, how close to the sun is the vertex of the path?

A) 39 million mi
B) $7.4$ million mi
C) $1.4$ million mi
D) $4.8$ million mi