Which of the following is most likely the next step in the series?
A.

Answer:
D.
Step-by-step explanation:
If you look at the pattern, the first shape (square) has four sides. Then, you have 5 sides, and finally, 6 sides.
Thus, a pattern of 4, 5, 6. So, the next shape must have 7 sides, leaving the only possible answer as D.