Final answer:
Beethoven's third period is characterized by experimentation with counterpoint and fugue, showcasing a transition from Classical to Romantic ideals in music. The correct option is a.
Step-by-step explanation:
Ludwig van Beethoven's third period of composition is characterized by a deep emotional depth and complexity, utilizing experimentation with counterpoint and fugue.
During this era, Beethoven pushed the boundaries of musical structure and expression, demonstrating a profound transformation from the Classical traditions to embrace the Romantic ideals.
His late works, such as the late string quartets and the Choral Symphony (Ninth Symphony), often involve intricate counterpoint and a bold use of harmony and rhythm that reflected his ongoing innovation as a composer. The correct option is a.