49.
Your Answer is
Correct Answer is A
Explanation
The underlined part is a complete sentence before and after, so it is correct to use the coordinating conjunction and to connect.
B item: which guides the attributive clause, which needs to be the subject or object in the attributive clause, and the following sentence does not lack the subject or object.
Item C: who is cannot be connected with the following sentence, wrong.
Item D: There is no conjunction to connect two sentences, wrong.