Problem Statement

Data Sufficiency for c Plus d from a Difference of Squares The question below is followed by two statements (I) and (II). Answer using these instructions: Mark (A) if the question can be answered by one of the statements alone but not by the other. Mark (B) if the question can be answered by using either statement alone. Mark (C) if the question can be answered using both statements together, but cannot be answered using either statement alone. Mark (D) if the question cannot be answered. What is the value of (c + d)? (I) c^2 - d^2 = 5 (II) c - d = 1