Respuesta :
Answer: Adverb Clause, have embraced .
Explanation: A subordinate clause, is a part of a sentence that doesn't have a meaning by itself, it needs the main clause to make sense. In this case, the subordinate clause is "After being recognized as players of an official sport in 2001" and the main clause is "Ultimate Frisbee athletes have embraced many new competitive opportunities". The subordinate clause in this example is an Adverb clause, because it starts with the adverb "After" and it modifies the verb "have embraced."