The formula for the Schwarzschild radius is
$\begin{align*}r_S = \frac{2 G M}{ c^2}\end{align*}$
where $G$ is the universal gravitational constant, $c$ is the speed of light, and $M$ is the mass of the black hole. Plugging in $M = 5.98 \cdot 10^{24} \mbox{ kg}$ gives
$\begin{align*}r_s = \frac{2 \cdot 6.67 \cdot 10^{-11} \;\mathrm{m}^2\mathrm{/}\mathrm{(}\mathrm{kg}\;\mathrm{s}^2\mathrm{)} \...$
Therefore, the correct answer is (C), $1 \mbox{ cm}$ .

Solution to 1996 Problem 67