Consider the following characteristics of contours:1. A uniform slope is indicated when contour lines are uniformly spaced.2. Contour lines cannot end anywhere but can close on themselves.3. A set of closed contours indicates depression or a summit, according to the lower or higher values being respectively inward.Which of the above statements are correct?

• A. 1 and 2 only
• B. 1, 2 and 3
• C. 1 and 3 only
• D. 2 and 3 only