Which statement best explains how Brutus's tragic flaw reveals the theme that citizens are persuaded by charismatic leaders?

Read the excerpt from act 2, scene 1, of The Tragedy of Julius Caesar.

BRUTUS. Let 'em enter.

[Exit LUCIUS]

They are the faction. O conspiracy,
Shamest thou to show thy dangerous brow by night,
When evils are most free? O then by day
Where wilt thou find a cavern dark enough
To mask thy monstrous visage? Seek none, conspiracy.
Hide it in smiles and affability;
For if thou path, thy native semblance on,
Not Erebus itself were dim enough
To hide thee from prevention.

[Enter the conspirators: CASSIUS, CASCA, DECIUS BRUTUS, CINNA, METELLUS CIMBER, and TREBONIUS]

CASSIUS. I think we are too bold upon your rest.
Good morrow, Brutus. Do we trouble you?

BRUTUS. I have been up this hour, awake all night.
Know I these men that come along with you?

CASSIUS. Yes, every man of them; and no man here
But honours you; and every one doth wish
You had but that opinion of yourself
Which every noble Roman bears of you.

a. Because Brutus is power-hungry and charismatic, he leads other citizens to conspire to kill Caesar.
b. Because Brutus is easily manipulated by others, he falls for Cassius's flattery and joins the conspiracy.
c. Because Brutus is honorable and loyal to the republic, he agrees to help keep Caesar from the throne.
d. Because Brutus is easily persuaded by others, he sides with Caesar in his quest to be king.