Final answer:
The best transition to use at the beginning of the third sentence to contrast graduation rates between schools with and without music programs is 'Conversely.'
Step-by-step explanation:
The question pertains to selecting the best transition word at the beginning of the third sentence of a provided paragraph that discusses the impact of music programs on student graduation rates. The correct transition word to use is Conversely, as it introduces a contrast between the graduation rates of schools with music programs and those without. The remaining options (Finally, Similarly, Specifically) do not appropriately represent the shift from a higher graduation rate to a lower one that is evident in the text.