Final answer:
Nobles and senators were concerned about Julius Caesar's possible military dictatorship and reduction of the Senate's influence, which led to his assassination.
The correct option is A.
Step-by-step explanation:
The concerns expressed by nobles and senators about Julius Caesar focussed primarily on the fear of a military dictatorship and the erosion of the Senate's power.
As Caesar's influence grew after his victory in the civil war against the Roman Senate, he declared himself dictator, first temporarily, and later for life. This move, along with the passage of laws that limited the terms of governors, significantly reduced the power of the Senate, leading to resentment among the aristocratic class.
This deep-seated fear of autocracy, coupled with Caesar's accumulation of power, led to a conspiracy formed by senators who hoped to preserve the Republic, ultimately culminating in his assassination in 44 BCE.
The correct option is A.