Answer:
The option promotes
Step-by-step explanation:
The reason that the word promotes would be used is actually very straightforward.
In grammar, whenever someone is talking about a single thing, they add an s onto the thing's action - almost like they're put a plural ending onto a singular noun's action!
It's the same when you're talking about a group of things: "The birds migrate()"
As you can see, no s needs to be added!
I hope this was really helpful! Tell me if you need any more help or clarification.