AT&T is focusing on its future.Shares of AT&T (T -0.48%) jumped 10.6% in September, according to data provided by S&P Global Market Intelligence. A couple of factors drove that rally. AT&T agreed to sell its remaining stake in DirecTV to its partner. The company also provided investors with an optimistic outlook for what's ahead. Here's a closer look at why these catalysts drove the telecom stock higher last month.Its future is coming into a clearer focusAfter much speculation, AT&T revealed that it agreed ...