Tatsouka 2009

What is the value of $8$ $\dfrac{4}{5}$ $-$ $5$ $\dfrac{3}{4}$?
A. $3\dfrac{1}{20}$
B. $\dfrac{7}{9}$
C. $\dfrac{10}{9}$
D. $1$
E. $\dfrac{51}{20}$