Express the Rational Number as a Fraction of Integers $0.6666 \ldots$

Multiple Choice

Express the rational number as a fraction of integers.
- $0.6666 \ldots$

A) $\frac { 2 } { 33 }$
B) $\frac { 6 } { 999 }$
C) $\frac { 66 } { 999 }$
D) $\frac { 2 } { 3 }$