Final answer:
The correct answer is option A: Although I enjoy running, I would never want to run a marathon
Step-by-step explanation:
The correct punctuation pattern for a complex sentence is:
A. Although I enjoy running, I would never want to run a marathon.
In this sentence, the subordinating conjunction 'although' introduces the dependent clause 'I enjoy running', and a comma is used to separate it from the independent clause 'I would never want to run a marathon'.