To which musical period does Mendelssohn belong?

Mendelssohn is primarily associated with the Romantic period of music, which is characterized by emotional expression, individualism, and an emphasis on lyrical melodies. He was active during the early to mid-19th century, a time when music began to explore more profound emotional ranges and personal themes compared to the earlier Classical period, which focused more on structure and form.

Mendelssohn's works often incorporate the Romantic ideals of nature, imagination, and personal reflection, as seen in his famous compositions like "A Midsummer Night's Dream" overture and his "Violin Concerto." His music blends elements of Classical form with Romantic expressiveness, making him a significant figure in the evolution of Romantic music. The other options either reference periods that are earlier or later than Mendelssohn’s primary activity as a composer, hence they do not accurately reflect his contributions or the characteristics of his musical output.