Determine the Period and Amplitude Of $y = 5 \cos \left( \frac { x } { 13 } + \frac { \pi } { 5 } \right)$

Multiple Choice

Determine the period and amplitude of $y = 5 \cos \left( \frac { x } { 13 } + \frac { \pi } { 5 } \right)$ .

A) period: $\frac { 2 \pi } { 13 }$ ; amplitude: 5
B) period: $26 \pi$ ; amplitude: 5
C) period: $13 \pi$ ; amplitude: 10
D) period: $\frac { \pi } { 13 }$ ; amplitude: 5
E) period: $- \frac { 2 \pi } { 13 } ;$ amplitude: $- 5$