Final answer:
In 'The Tragedy of Julius Caesar,' a monologue is a lengthy speech by a single character to convey their thoughts, even with others on stage. Without specific content, Speech 4 (Caesar) is likely the monologue due to Caesar's prominent role and character traits.
Step-by-step explanation:
In The Tragedy of Julius Caesar, a monologue is a speech presented by a single character to express their thoughts out loud, often to other characters who are on stage but do not interrupt. Therefore, to answer which speech from the given scene is most clearly an example of a monologue, one would look for a lengthy speech made by one character, regardless of others being present. Without the specific content of Speech 1, 2, 3 or 4, we cannot decisively choose an option. However, speech 4, typically associated with Caesar, is likely to be monologic given Caesar's pivotal role in the play and his propensity to deliver long, uninterrupted speeches that convey his thoughts and decisions to others around him, or to the audience.