Answer:
C. Logos
Step-by-step explanation:
Rhetorical appeal use in this sentence is logos because there is a situation where there costs and benefits from building a library. There are two parts of the sentence, on the first part there are economics costs for building and it is written to show the real prize of building institution. In the second part, the readers can see what local businesses gain, not only readers who go to the library. The whole situation is described as logical, with benefits and costs and effects.