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

Answer:
Option (A)
Step-by-step explanation:
In the given picture,
Figure (1) → quadrilateral (Number of sides = 4)
Figure (2) → pentagon (Number of sides = 5)
Figure (3) → hexagon (Number of sides = 6)
Here we find number of sides are increasing by 1,
Therefore, next structure in the series will be having 7 sides.
Option (A) will be the correct option.