Find the Indicated Probability by Using the General Addition Rule $\frac { 10 } { 9 }$

Multiple Choice

Find the indicated probability by using the general addition rule.
-A spinner has regions numbered 1 through 21 . What is the probability that the spinner will stop on an even number or a multiple of 3 ?

A) $\frac { 10 } { 9 }$
B) 17
C) $\frac { 1 } { 3 }$
D) $\frac { 2 } { 3 }$