would it be D. Conjuction. The main clause of the sentence is "it still contained helpful information"<br/><br/>the dependent clause is the begining of the sentence joined by the main clause by the conjuction although.<br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/>In the sentence “Although the book was more than 50 years old, it still contained<br/><br/>helpful information,” the word <br/><i>Although <br/><br/>is a/an<b><br/><br/>A. <br/>verb. <b>C. <br/><br/>adjective.<b><br/><br/>B. <br/>preposition. <b>D. <br/><br/>conjunction<br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/><br/></b></b><br/></b></b><br/></i><br/><br/>