The coordinates of a point dividing the line segment joining (1, 2, 3) and (4, 5, 6) internally in the ratio 2:1 is:
(a) (3, 4, 5)
(b) (2.5, 3.5, 4.5)
(c) (2, 3, 4)
(d) (2.5, 4, 5.5)