Which of the following correctly punctuates a nonessential expression?

ASpain attempted reforms, which proved largely ineffectual, to help the condition of the Native Americans.

BSpain attempted reforms which proved largely ineffectual, to help the condition of the Native Americans.

CSpain attempted reforms, which proved largely ineffectual to help the condition of the Native Americans.

DSpain attempted reforms which proved largely ineffectual to help the condition of the Native Americans.