A Person with Normal Eyesight Uses a Converging Lens of Focal

Multiple Choice

A person with normal eyesight uses a converging lens of focal length $10 \mathrm {~cm}$ as a magnifying glass to finish an engraving job. To see detail, he holds the lens very close to his eyes. At what minimum distance from the job must he hold the lens?

A) $30 \mathrm {~cm}$
B) $20 \mathrm {~cm}$
C) $7.1 \mathrm {~cm}$
D) $9.4 \mathrm {~cm}$
E) $14 \mathrm {~cm}$