Which is the best example of a response to an external stimulus?

A) drinking water after a long run
B) avoiding the sun by looking for food at night
C) a hungry bear hunting for food
D) falling asleep in the treetops of a forest

Amylase becomes denatured at a temperature of 80°c. during an experiment to study the effect of varyingtemperature on enzyme activity, amylase’s reactivity with starch was measured at body temperature (37°c), andthen again at an increased temperature of 42°c. how would this increase in temperature affect the experiment

Me with these questions image attached

What organ is the first to receive nutrients that have been absorbed from the digestive tract?