A biologist took a count of the number of migrating waterfowl

 The correct option is (B). Its image is attached below.

Step-by-step explanation:  We are given to select the correct option that is  most likely the next step in the series.

From the given figures, we see that

the first figure contains 5 lines of blue color, out of which 3 are vertical and 2 are horizontal,

the first figure contains 4 lines of red color, out of which 2 are vertical and 2 are horizontal,

the third figure contains 3 lines of blue color, out of which 2 are vertical and 1 is horizontal.

Therefore, following the pattern, we arrive at

the fourth figure will contain 2 lines of red color, out of which 1 is vertical and on is horizontal.

Thus, option (B) is CORRECT.

The image is shown below.