Final answer:
The sentence 'The rain falls like the sun, rising upon the mountains' uses a simile, a type of figurative language that compares two things using 'like' or 'as'.
Step-by-step explanation:
In the sentence 'The rain falls like the sun, rising upon the mountains,' the most appropriate type of figurative language used is a simile. This is because the sentence is making a comparison between the way the rain falls and the action of the sun rising upon the mountains using the word 'like.' A simile is a specific type of figurative language that explicitly uses words such as 'like' or 'as' to draw a comparison between two different things, providing a vivid image or idea. Unlike a metaphor, which makes a direct comparison without using 'like' or 'as,' a simile clearly signals the comparison with these specific words.