Find the Limit, If It Exists $\lim _ { h \rightarrow 0 } \frac { ( x + h ) ^ { 3 } - x ^ { 3 } } { h }$

Multiple Choice

Find the limit, if it exists.
- $\lim _ { h \rightarrow 0 } \frac { ( x + h ) ^ { 3 } - x ^ { 3 } } { h }$

A) Does not exist
B) 0
C) $3 x ^ { 2 }$
D) $3 x ^ { 2 } + 3 x h + h ^ { 2 }$