Final answer:
The coordinating conjunction 'but' connects two independent clauses and introduces an opposing idea.
Step-by-step explanation:
The coordinating conjunction in the sentence is but, and its purpose is to connect two independent clauses and introduce an opposing idea.
Coordinating conjunctions like but are used to join words, phrases, or clauses of equal importance in a sentence. They help in creating a balanced sentence structure and adding contrast or opposition between ideas.
Learn more about Coordinating conjunctions in English grammar