Simplify the Expression $$\left( 3 n ^ { 2 } \right) \cdot \left( 5 n ^ { 3 } \right)$$

Multiple Choice

Simplify the expression. Assume all variables represent nonzero real numbers.
- $$\left( 3 n ^ { 2 } \right) \cdot \left( 5 n ^ { 3 } \right)$$

A) $8 n ^ { 5 }$
B) $15 n ^ 5$
C) $8 n ^ { 6 }$
D) $15 \mathrm { n } ^ { 6 }$