Consider a fuzzy set old as defined below Old = {(20, 0.1), (30, 0.2), (40, 0.4), (50, 0.6), (60, 0.8), (70, 1), (80, 1)} Then the alpha-cut for alpha = 0.4 for the set old will be

(A) {(40, 0.4)}

(B) {50, 60, 70, 80}

(C) {(20, 0.1), (30, 0.2)}

(D) {(20, 0), (30, 0), (40, 1),(50, 1), (60, 1), (70, 1), (80, 1)}

Answer D.

Explanation.

Set elements with membership .4 or greater than .4.