Final answer:
Bohdan Khmelnitsky led an uprising against Polish rule and defeated Poland in the Khmelnytsky Uprising of the mid-17th century.
Step-by-step explanation:
Bohdan Khmelnitsky was a Ukrainian hetman of the Zaporozhian Cossack Hetmanate who led an uprising against Polish rule in the mid-17th century. The correct answer to the question 'Who did Khmelnitsky fight and defeat?' is c. Poland. This revolt, known as Khmelnytsky Uprising or the Cossack-Polish War, took place from 1648 to 1654 and resulted in a significant defeat for the Polish-Lithuanian Commonwealth and a shift in the control of territories in Eastern Europe.