Add or Subtract as Indicated $15 \frac { 2 } { 7 } - 7 \frac { 4 } { 7 }$

Multiple Choice

Add or subtract as indicated. Write the answer in lowest terms.
- $15 \frac { 2 } { 7 } - 7 \frac { 4 } { 7 }$

A) $7 \frac { 5 } { 7 }$
B) $22 \frac { 5 } { 7 }$
C) $7 \frac { 4 } { 7 }$
D) $21 \frac { 5 } { 7 }$