The sentence in which the pronoun and the antecedent are not in agreement is option C. If the bus is late, he will be late to class. In the first clause, the subject of the sentence is the word "bus", and in the next clause, the subject changed to "he" and the pronoun he does not clearly state its antecedent.
What's the sentences? I only see 1? I don't understand.
There is a number of words or phrases that you could use to help smooth the transition between sentence 1 and sentence 2, and here are some of them: also, in addition, additionally, furthermore, moreover, on top of that, etc. The meaning of the second sentence adds on top of the first one - so any of these transition words would be a good choice.
It's like a child growing up they grow
B because it talks about expressing individuality.