Which of these quotes with a subordinating adverb is punctuated correctly?
A. Even so when I was invited to attend an important author event on the East Coast; a friend took me in hand.
B. Even so when I was invited to attend an important author event on the East Coast a friend took me in hand.
C. Even so, when I was invited to attend an important author event on the East Coast, a friend took me in hand.
D. Even so, when I was invited to attend an important author event on the East Coast. A friend took me in hand.”