Ahistorian argues that the roman leader julius casear was assassinated because he was secretly plotting to over throw the roman republic and declare himself emperor of rom which of the following if true, would be a strong counterclaim to the historians claim

Personal letters written by Julius Caesar indicate that he believed that Rome should always remain a republic.

Explanation:

Such is a mere guess by said historian, there is no evidence proving such but knowing the ambitious nature of Julius Caesar, it can be assumed this was his end goal in order to establish a tyrannical despotic monarchy where his line would continue to rule Rome, in order to leave an everlasting legacy for those within his dynasty.

The answer to your question is c