I will answer your question, but you may want to do a search on the English Grammar Revolution to help you with future questions in this subject. Anyways, the verbal in this sentence is "hoping to begin". This means it is a participle, but despite the seeming obviousness of the answer from there I don't want to go with either A or B. However, I do believe if either one is a choice I would go with B rather than A.
I think the answer is after because heyday means a period of success or popularity