Select the Answer That Corrects the Modifier Errors

Select the answer that corrects the modifier errors.
-At the age of six, my mother was promoted to full partner in her law firm.

A) When I was six, my mother was promoted to full partner in her law firm.
B) At the age of six in her law firm, my mother was promoted to full partner.
C) In her law firm when I was at the age of six, my mother was promoted to full partner.
D) My mother was promoted to full partner in her law firm at the age of six.