Which of these sentences is punctuated correctly? my family visited washington,

My family visited Washington D.C., and spent three days exploring The Smithsonian.

A plot is the main story line of a work consisting of a chain of events related by cause and effect.

Explanation:

Plot is a term used in literature, which stands for a main part of the story and the events that constitute this story. This includes sequence of events in which we get to know the characters, the setting and certain themes explored in the story. The plot is the most important element of every story, which cannot be omitted.