He wants to convince readers that Buddhism is worth studying
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.
The gerund phrase in the given sentence would be: Training show dogs. This gerund phrase is used as the direct object. The answer is option B. A gerund is a word that ends in -ing, but functions as a noun. A gerund phrase consists of the gerund plus other words that modifies.