Add or Subtract the Radical Expressions as Indicated, If Possible $$z ^ { 2 } \sqrt { 18 z } + 7 \sqrt { 200 z }$$

Multiple Choice

Add or subtract the radical expressions as indicated, if possible. $$z ^ { 2 } \sqrt { 18 z } + 7 \sqrt { 200 z }$$

A) $\left( 3 z ^ { 2 } + 70 \right) \sqrt { 2 z }$
B) $\left( 18 z ^ { 2 } + 1400 \right) \sqrt { z }$
C) $\left( z ^ { 2 } + 7 \right) \sqrt { 218 z }$
D) Cannot be simplified further