Find the Indicated Partial Sum for the Given Sequence with the Given

Multiple Choice

Find the indicated partial sum for the given sequence with the given first term and general term.
- $\mathrm { s } _ { 4 } , \mathrm { a } _ { 1 } = 4 , \mathrm { a } _ { \mathrm { n } } = 20 \mathrm { a } _ { \mathrm { n } - 1 }$

A) $- 7582$
B) $- 7581$
C) 8419
D) 673,684