Add the Radical Expressions $$z ^ { 2 } \sqrt { 18 z } + 7 \sqrt { 98 z }$$

Multiple Choice

Add the radical expressions.
- $$z ^ { 2 } \sqrt { 18 z } + 7 \sqrt { 98 z }$$

A) $\left( 3 z ^ { 2 } + 49 \right) \sqrt { 2 z }$
B) $\left( 18 z ^ { 2 } + 686 \right) \sqrt { z }$
C) $\left( z ^ { 2 } + 7 \right) \sqrt { 116 z }$
D) Cannot be simplified further