Answer:
Resistive force from canoe in backward direction
Step-by-step explanation:
As per Newton's third law of motion for every action, there is an equal reaction and that too in the direction opposite the direction of main action.
Here, the action reaction pair is the contact point of Emilio or the Canoe.
When Emilio tried to jump on the dock, he exerted an action force i.e the KE+PE in the forward direction but while jumping he pushed behind the canoe which in turn exerted resistive frictional force in the backward direction on Emilio which restricted him from jumping exactly on the dock .