Write set {1, 5, 15, 25,…} in set-builder form.

• A. {x: either x=1 or x=5n, where n is a real number}
• B. {x: either x=1 or x=5n, where n is a integer}
• C. {x: either x=1 or x=5n, where n is an odd natural number}
• D. {x: x=5n, where n is a natural number}