Find the Domain $$z ( a ) = \sqrt { a + 5 }$$

Multiple Choice

Find the domain. Write the answer in interval notation. $$z ( a ) = \sqrt { a + 5 }$$

A) $( - 5 , \infty )$
B) $( - \infty , \infty )$
C) $[ 0 , \infty )$
D) $[ - 5 , \infty )$