Question 17.

The following excerpt serves as an essential source for comparing the difference in the attributes of the elephant seals: ["...Yet there are other differences between the males from the late 1960s and their great-great-grandsons: Modern males exhibit more individual diversity, and their calls are more complex. While 50 years ago the drumming pattern was quite simple and the dialects denoted just a change in tempo, Casey explained, the calls recorded today have more complex structures, sometimes featuring doublets or triplets. . . ."]

In the late 1960s, the elephant seal calls were marked by having a simple drumming pattern which later transformed into calls with marked individual diversity and sophistication. Additionally, the dialects that were present in the 1960s were not evident during the study undertaken in the early 2010s, thereby indicating a decrease in the regional variations in the calls. These elements are aptly captured in Option B.