I am asking this question because I have seen that OG clearly explains that an answer choice is wrong because " and also" is redundant. However, I have also seen the appearance of " and also" in their own words. I mean they write things with this phrase but at the same time say it is redundant in the explanations( which means it is not the right usage?). The same case is for" comma, which". I studied some grammar prep book saying "comma, which" cannot refer to the preceding clause in the GMAT. Is that true?
So "and also" is definitely wrong? Whenever you see it appear in the answer choice, you should eliminate that choice? Or it is just redundant but grammatically right and we should keep it as the right answer if no other better choices appear?
THANKS A LOT!