21 -6 - NO a) D : {all real numbers}, R: {all real numbers Ob) D: {all real numbers), R; {y >0} O c) D: all real numbers), R: {y < 0} O d) D: {x>0}, R: {all real numbers

The domain is
[tex]D\colon\mleft\lbrace x\ge0\mright\rbrace[/tex]and the range
[tex]R=\text{all real numbers}[/tex]Then, the answer is d)