To solve this question, the user needs to know about the history of Washington D.C. and the meaning of its name.

The correct answer is:

B. District of Columbia

Explanation:

Washington D.C. is the capital city of the United States of America. The city was named after George Washington, the first President of the United States, and Christopher Columbus, the explorer who discovered the New World. "D.C." stands for "District of Columbia," which is a federal district that serves as the capital of the United States. The district was created in 1790 by the U.S. Congress as a result of the Residence Act, which designated a permanent capital for the country. Therefore, option B is the correct answer.

Option A is incorrect because there is no such thing as the Directorate of Columbus.

Option C is incorrect because "Democratic Columbia" is not a term used to describe Washington D.C.

Option D is incorrect because the correct term is "District of Columbia," not "District of Columbus."