Find the measure of $\angle ABC$ in parallelogram $ABCD$. Parallelogram $ABCD$ has base side $DC$, and the side opposite to the base is labeled 16 units. The length of side $BC$ is labeled 7 units. The measure of angle $A$ is 120 degrees. Diagonals $AC$ and $BD$ intersect at point $E$. The measure of angle $ADE$ is labeled 43 degrees. The length of sides $DE$ and $CE$ are labeled 10.2 units and 7 units, respectively.
a) 66.2 degrees
b) 76.8 degrees
c) 83.8 degrees
d) 93.4 degrees
