Without Graphing the Function, Determine Its Amplitude or Period as Requested

Multiple Choice

Without graphing the function, determine its amplitude or period as requested.
- $y = \frac { 7 } { 6 } \sin \left( - \frac { 8 \pi } { 3 } x \right) \quad$ Find the period.

A) $\frac { 7 } { 4 }$
B) $\frac { 2 } { 3 }$
C) $\frac { 3 \pi } { 2 }$
D) $\frac { 16 \pi } { 7 }$