A) He is lazy. He also doesn't study/He doesn't study too.
B) He is lazy. He doesn't study either.
According to Swan Practical English Usage (47) which says that after an affirmative sentence which is followed by a negative statement we must use also/too/as well, sentence A is correct but in my own point of view and according to EnglishPage.com sentence B is correct.
There is also another question in English Language and Usage community Can “too” be used with negative verb? which made me more confused.
Would you please tell me which one of these two sentences is correct? Can they be both correct with different meanings?