The answer is C. most active
The superlative form means that among the items being compared, that items is the "most" or "least" of them all.
B.
common, concrete, neither, countable
Answer: Hope this helps
Explanation: Juneteenth – also known as Freedom Day, Jubilee Day, Liberation Day, and Emancipation Day – is a holiday celebrating the emancipation of those who had been enslaved in the United States.