The Measurement Is $2 \frac { 15 } { 21 }$

Multiple Choice

The measurement is $2 \frac { 15 } { 21 }$ yd. Find the precision and the greatest possible error of the measurement.

A) $\frac { 1 } { 21 }$ yd., $\frac { 1 } { 42 }$ yd.
B) $\frac { 1 } { 21 }$ yd., $\frac { 1 } { 21 }$ yd.
C) $\frac { 1 } { 42 }$ yd., $\frac { 1 } { 42 }$ yd.
D) $\frac { 1 } { 42 }$ yd., $\frac { 1 } { 21 }$ yd.
E) none of these