एक समोच्च रेखा (contour line) किसी कटक रेखा (ridge line) या घाटी रेखा को किस कोण पर काटती है?

Consider the following statements about the characteristics of contours: I. Closed contour lines with higher values inside show a depression/lake. II. A contour is an imaginary line joining points of equal elevation. III. Closely spaced contours indicate a steep slope. IV. Contour lines can cross each other in the case of an overhanging cliff. Which of these statements are correct?

Closed contour lines with higher elevation values inside represent a: