Multiply and Reduce Your Answer to Lowest Terms $\frac { 1 } { 9 } \cdot \frac { 3 } { 7 }$

Multiple Choice

Multiply and reduce your answer to lowest terms. $\frac { 1 } { 9 } \cdot \frac { 3 } { 7 }$

A) $\frac { 1 } { 3 }$
B) $3$
C) $63$
D) $\frac { 1 } { 63 }$
E) $\frac { 1 } { 21 }$