There is a lot of key information missing from your questions.
(1) Your question is confusing but I can say that "into", followed by the indefinite article, is correct in the sentence as it stands. But it also needs a full stop.
"Every child needs special care and attention so that he or she will grow up into a responsible human being".
Another version of this sentence:
"Every child needs special care and attention so that he or she will grow up to be a responsible human being".
In (2) and (3) you have told us that B is the answer, but the answer to what? You need to tell us what the questions are.
not a teacher