Find the Largest Open Interval Where the Function Is Changing $\mathrm { f } ( \mathrm { x } ) = \sqrt { 4 - \mathrm { x } }$

Multiple Choice

Find the largest open interval where the function is changing as requested.
-Decreasing $\mathrm { f } ( \mathrm { x } ) = \sqrt { 4 - \mathrm { x } }$

A) $( 4 , \infty )$
B) $( - \infty , 4 )$
C) $( - \infty , - 4 )$
D) $( - 4 , \infty )$