Solve the Radical Equation, and Check All Proposed Solutions $$\sqrt { 6 x + 55 } = x$$

Multiple Choice

Solve the radical equation, and check all proposed solutions.
- $$\sqrt { 6 x + 55 } = x$$

A) $\{ - 11 \}$
B) $\varnothing$
C) $\{ 11 \}$
D) $\{ - 5,11 \}$