Final answer:
Casimir Pulaski, a Polish aristocrat, died in 1779 fighting for the American colonies during the American Revolutionary War and is known as the 'Father of the American Cavalry'. The correct option is (A)
Step-by-step explanation:
The Polish aristocrat who died in 1779 fighting for the American colonies was A) Casimir Pulaski. Pulaski is a celebrated figure in American and Polish history alike, known for his military contributions during the American Revolutionary War. He was a member of the Polish nobility and fought against Russia in Poland before being recruited by Benjamin Franklin to assist the American cause. Pulaski is most recognized for his efforts in reforming and leading the American cavalry, ultimately earning the title 'Father of the American Cavalry'. He sustained mortal wounds during the Siege of Savannah and hence died for the revolutionary cause. Neither B) Tadeusz Kościuszko, C) Ignacy Paderewski, nor D) Henryk Sienkiewicz had the distinction of dying in 1779 while fighting for the American colonies.