Why are Cassius and Brutus feuding?

Basically,

Brutus accused Lucias pella of taking bribes (persuade someone)to act in there favor) , while Cassius is in the mean time seeking to protect bella.  Brutus thought that they killed Caesar because they were seeking justice and the good of Rome itself.

i don't think it's a good idea to threaten anyone at all.

the answer should be d) he was one of those young thousands who greeted the war with a certain amount of relief, welcoming the liberation from webs of tangled emotion" since it is the best option because it shows his desire to free himself. 

hope this answer you! have a great day.