Which of the following best characterizes William Shakespeare's contributions to literature?

William Shakespeare's contributions to literature are best characterized by his diversity and originality in character development. He is acclaimed for creating a wide array of complex characters that embody a range of human emotions and motivations, from the tragic to the comedic. This depth allows his characters to resonate with audiences across different cultures and eras.

His works include not only iconic tragedies, such as "Hamlet" and "Othello," but also comedies like "A Midsummer Night's Dream" and historical plays such as "Henry V." Each genre showcases his ability to explore the human condition in various contexts, providing intricate and multifaceted portrayals of individuals. This complexity is one of the hallmarks of Shakespeare's storytelling, setting a standard for character development that remains influential in literature today.

The other options do not accurately reflect the scope of Shakespeare's work. He did not solely focus on romantic poetry, nor was he primarily a children's author or a writer of historical non-fiction. His literary repertoire is characterized by its diverse genres and profound insights into human nature.