Since my proposal was ignored I will try my luck in answering the question because I need merits too. 
Yes, Bitcoin does have a solution and it is called the proof-of-work algorithm. So to alter "the message" (a block of transactions in our case) as in the classic Byzantine Generals problem and to make it look authentic by guessing a new nonce, one would need to use more Hash Power than the entire network. Since the current Hash Rate is around 23 million TH/s, to achieve that they would need to buy 1.5 million of Antminer S9.
Btw my proposal remains in force in case you'll find it helpful.
Quote
Question B)
Does Bitcoin have an adaquete solution to the Byzantine Generals problem?
Why not or what is it?
Does Bitcoin have an adaquete solution to the Byzantine Generals problem?
Why not or what is it?
Yes, Bitcoin does have a solution and it is called the proof-of-work algorithm. So to alter "the message" (a block of transactions in our case) as in the classic Byzantine Generals problem and to make it look authentic by guessing a new nonce, one would need to use more Hash Power than the entire network. Since the current Hash Rate is around 23 million TH/s, to achieve that they would need to buy 1.5 million of Antminer S9.
Btw my proposal remains in force in case you'll find it helpful.