$15 ^ { 13 } + 6 \cdot 15 ^ { 13 } + 8 \cdot 15 ^ { 13 }$ What is the result of this operation?\\ A) $15 ^ { 15 }$\\ B) $15 ^ { 14 }$\\ C) $14 \cdot 15 ^ { 13 }$\\ D) $10 \cdot 16 ^ { 13 }$\\ E) $16 ^ { 13 }$