Is the sentence "after starring at each other for a few minutes, the snake slithered away" a simple, compound or complex sentence?

A simple sentence contains one clause, which just means one subject one verb.  She runs.  Go.  Freddie happily walked.  A compound sentence includes two or more independent clauses. An independent clause is a clause that doesn't need another clause to make sense.  For example: Sally eagerly jumped up and down, and George anxiously waited  for the surprise.   Sally eagerly jumped up and down.  George anxiously waited for the surprise.  Both of these clauses make sense by themselves, and that makes them independent.  A compound sentence also includes FANBOYS (for, and, nor, but, or, yet, so) with a coma.  A complex sentence has at least one independent clause plus at least one dependent clause with the use of a subordinating conjunction.  One of the most popular subordinating conjunction is because, and it can be used in the beginning or middle of the sentence.  

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Umm whatever he said it didn't make sense

Istrongly feel d is the answer but c is also a strong possibility