The lengths of the 3 sides of a certain triangle are related as shown below, where n is the length of the shortest side of the triangle.

3n, 4n, 6n

Which of these name the lengths of the sides for another triangle, similar to the first triangle, for any value n ≥ 1?
a 9n, 12n, 30n
b 3n + 2, 4n + 4, 6n + 6
c 1.5n, 2n, 3n
d 3n + 1, 4n + 1, 6n + 1