Find the Largest Open Interval Where the Function Is Changing $f ( x ) = - \sqrt { x + 3 }$

Multiple Choice

Find the largest open interval where the function is changing as requested.
-Decreasing $f ( x ) = - \sqrt { x + 3 }$

A) $( 3 , \infty )$
B) $( - \infty , 3 )$
C) $( - 3 , \infty )$
D) $( - \infty , - 3 )$