A. The king of Scotland in the early 14th century was the great Robert the Bruce, and due to his victories he is remembered as a national hero in Scotland because these victories lead to the independence of Scotland from England.
Phrases that begin with "due to" can only modify nouns, not verbs. Also "lead" is present tense "led" suits better
B. When Robert the Bruce, king of Scotland in the early 14th century won victories against England, this resulted in independence from England, and he is remembered as a national hero in Scotland.
"this" doesn't have a clear referent. Only logical referent would be victories, but "victories" is plural
C. Robert the Bruce, King of Scotland in the early 14th century is remembered as a national hero in Scotland, because his victory resulted in the independence of Scotland from England.
CorrectD. Robert the Bruce king of Scotland in the early 14th century, winning victories that resulted in the independence from England, and he is remembered as a national hero in Scotland.
"and" connects same type of phrases. Here we have a DC and IC connected by "and". Also we have double subject "Robert the Bruce... and he"
E. The king of Scotland in the early 14th century, Robert the Bruce, won victories with the results that, with the results that Scotland became independent from England and he is remembered as a national hero in Scotland.
why repeat with the results that?