The example with the subordinating conjunction is option C: "Not only did she dye her hair purple, but she also pierced her ears." The subordinating conjunction "Not only" introduces a dependent clause, creating a complex sentence structure.
The example that contains a subordinating conjunction is:
C. Not only did she dye her hair purple, but she also pierced her ears.
A subordinating conjunction introduces a dependent clause, and in this case, "Not only" is the subordinating conjunction that signals the beginning of the dependent clause, "did she dye her hair purple." The subsequent independent clause, "but she also pierced her ears," is connected through the subordinating conjunction, creating a complex sentence structure.
In contrast, option A features a coordinating conjunction ("or") connecting two independent clauses, option B uses the coordinating conjunction "after" to link independent clauses, and option D employs a correlative conjunction ("or") to connect two independent clauses. These options feature coordinating conjunctions, not subordinating conjunctions, as they connect independent clauses or coordinate equal sentence elements.
In summary, option C contains a subordinating conjunction ("Not only") introducing a dependent clause, making it the correct choice.