It would be Nemo because that's who Dory is giving the leaf, or the direct object, to. You can think of it as the indirect object bouncing back from the direct object.
I would say the correct answer is B. hyperbole.
Hyperbole is a figure of speech that authors use when they want to exaggerate things. So this 'vegetable love' cannot possibly grow larger than empires - the poem just wants to demonstrate the power and intensity of this love by using the figure of hyperbole. A paradox would include two completely opposite things, and <em>vast </em>and <em>slow </em>are not opposites.
