A flute player hears two beats per second when the player compares the player$$s note to a $523$ Hz tuning fork. The player can match the frequency of the tuning fork by pushing in the "tuning joint" to shorten the player$$s flute slightly. What was the player$$s initial frequency? A$)519$ Hz B$)521$ Hz C$)525$ Hz D$)527$ Hz E$)531$ Hz