Digital SAT Reading and Writing Practice Question #261

Ecologists observed that the Bombus impatiens bumblebee preferentially visits Monarda fistulosa (a flower which produces high-yield nectar but has deep corolla tubes) on sunny days, but shifts its preference to Solidago canadensis (which has easily accessible, albeit lower-yield, nectar) on overcast days. Because the bees' flight muscles must maintain a minimum temperature for the extended hovering required to extract nectar from deep corollas, and because overcast days are generally cooler, the ecologists hypothesized that the shift in preference is driven by strict energetic constraints. If this hypothesis is true, it most logically suggests that ________