n$=1\mathrm{.}5$ The lens labeled $(C)$ has radii $12\mathrm{.}3$ cm and $19\mathrm{.}0$ cm $.$ Using the shape of the lens to assign the given radii and their signs, calculate the focal length of the lens. Give your answer with the correct positive or negative sign using the usual convention for lenses.

Hint: consider which side is more curved in the image to decide which radius corresponds to which side.

Image size: s M L Max

$($A$)$

$($B$)$

$($C$)$