Hello, the correct answer would be either A or D. B cannot be correct because it still remains a fragment. The same case is with C. A might be correct in the following sense: Since, they had traveled often. "Since" meaning - after that. And D might also be correct because if you delete "since", you are left with - "They had traveled often", which is a completely correct and completed sentence.
I wrote one but it won’t let me type it because it’s apparently not the ‘right answer’
The answer is C. An appositive phrase is where a noun is restated. "A town in Florida" is right next to the noun, St. Augustine. C. restates the noun in a different way, right next to the noun, St. Augustine.
