What do the data suggest about the effects of cane toads on the predatory behavior of black snakes in areas where the toads have been present for 40–60 years?
a. black snakes in areas where cane toads have been present for 40–60 years are just as likely to prey on cane toads as on native frogs.
b. black snakes will prey on cane toads in areas where cane toads have been present for 40–60 years, but not when offered a native frog instead.
c. black snakes will not prey on cane toads in areas where cane toads have been present for 40–60 years.