Multiply Write the Answer in Simplest Form $4 \frac { 1 } { 5 } \cdot 5$

Multiply. Write the answer in simplest form.
- $4 \frac { 1 } { 5 } \cdot 5$

A) 100
B) 21
C) 20
D) $9 \frac { 1 } { 5 }$