In an endothermic reaction, energy is absorbed which causes the object to heat up.
The focea centralis functions to promote daytime vision, being the site of concentrated photoreceptors called cone cells.
That pump you speak of is responsible for the active transport of sodium and potassium.
Here, Rabbit eats producer which is grass, so it is primary consumer.
In short, Your Answer would be "Rabbit"
Hope this helps!