TOEFL Listening: ETS-TOEFL听力机经 - HEM9VTIP0NS1O55PP$

Why does the professor talk about lions? A. To compare two ways that lions communicate with each other. B. To introduce the concept of signal reliability in the animal kingdom. C. To point out why lions often win fights against animals of other species. D. To explain some of the benefits of exaggerating one's own strength.