Find the complement C^c of the set C with respect to the space C if
(a) C = {x : 0 < x < 1}, C = {x : 5 /8 < x < 1}.
(b) C = {(x, y, z) : x² + y² + z² ≤ 1}, C = {(x, y, z) : x² + y² + z² = 1}.
(c) C = {(x, y) : |x| + |y| ≤ 2}, C = {(x, y) : x² + y² < 2}.