Why was William Clark chosen to accompany Lewis on an official exploratory mission? A. He had had formal education in a wide range of subjects. B. He was a trusted member of Jefferson's government. C. He was fluent in Indian languages D. He was a skilled cartographer.

The correct answer is D. He was a skilled cartographer. William Clark was born on August 1, 1770, in Caroline County, Virginia. He did not receive any formal education because he was educated at home. At the age of 20, he was commissioned as Captain in the Indiana militia by Governor of the Northwest Territory, General Arthur St. Clair. For the next six years, he took responsibilities in different missions and assignments until he decided to retire in his family's plantation. In 1803, without any political experience and because of his skills as an excellent mapmaker, he received an invitation from his friend Meriwether Lewis to share command of an expedition of the lands west of the Mississippi River. Neither did he have knowledge of the native languages.

The answer would be D.