For the Proportion, Find the Unknown Number N $\frac { 0.6 } { 4.2 } = \frac { 5 } { n }$

For the proportion, find the unknown number n.
- $\frac { 0.6 } { 4.2 } = \frac { 5 } { n }$

A) 21
B) 35
C) $2 \frac { 13 } { 25 }$
D) 3