The bird species Saltator grossus (the slate-colored grosbeak), which weighs about 45 grams, and Mniotilta varia (the collared gnatwren),which weighs about Yo grams, share territors m French Guiana with Thamnomanes caegius (the cinereous antshrike), which emits a loud alarm call when it edetects predators . Biologist Ari Martinez and colleagues, who studied the ecological community these species,share , hypothesized that since there is an inverse Felationship between body size and vulnefability to predation, there will also be an inverse relationship between body size and sensitivity to predator warning signals from neighboring species. Martinez and colleagues' hypothesis? Which finding, if true , would most directly support A. When Martinez and cóHeagues played T . caesius alarm calls, only birdspecies larger than S. grossus displayed predator -avoidance behavior. B. M. collaris displayed predator-avoidafic e behavior when Martinez and colleagues played T . caesius alarm calls as well as when the researchers played control sounds of random noise. C. Many bird species'smaller than S grossus displayed predator-avoidance behavior in response to T. caesius alarm calls played by Martinez and colleagues, but none smaller than M collaris did. D. M. collaris displayed predator-avoidan ce behavior in response to T caesius alarm calls played by Martinez and colleagues, whereas S grossus did not.