The meaning behind that simile is that ‘they’ are getting tons of gold like they were corn grains which if you’ve seen them, there’s a lot in just one corn. So basically those people were getting a lot of gold.
'D - Misplaced words' would be my answer. My trick is to say the sentence out loud and you'll hear that somethings wrong.
Answer:
I'm pretty sure it's an allusion!
Explanation:
Allusion: an expression designed to call something to mind without mentioning it explicitly