Select the phrase/connector/word-pair from the given three options to form a single sentence from the two sentences given below, implying the same meaning as expressed in the original sentences. The phrase/connector must appear at the beginning of the final sentence.
I. He wanted to see the movie before it was over.
II. He came home early. (i) Therefore (ii) Because (iii) So

'Therefore' is used to mention that something happens as a result of something else that has been mentioned before. For example - The new boots are lighter and softer, and therefore more comfortable to wear. It can't be used in the beginning. 'Because' and 'so' indicate a cause and effect relationship. They provide a reason for the occurrence of something. But 'so' appears between the 'cause' and the 'effect'. It cannot be used at the beginning. 'Because' can combine the two sentences. D is the answer. "Because he wanted to see the movie before it was over, he came early."