QUESTION $9$

What does $message contain after the following code executes?

$rate $=0\mathrm{.}1$;

if $(!$ is$\_$numeric$($$rate$))\{$

Smessage $=$ 'Rate is not a number.$\text{'}$;

$\}$ else if $($ $ rate $<mn\; id="EditorElement\_6146276">0</mn><mtext\; id="EditorElement\_6146211"></mtext><mi\; id="EditorElement\_6146212">\{</mi>$

Smessage $=$ 'Rate cannot be less than zero.$\text{'}$;

$\}$ else if $($ $ rate $>0\mathrm{.}2\{$

Smessage $=$ 'Rate cannot be greater than $20\%.\text{'}$;

$\}$ else $\{$

Smessage $=$ 'Rate is valid.$\text{'}$;

$\}$

a$.$ Rate is not a number.

b$.$ Rate cannot be greater than $20\%.$

c$.$ Rate cannot be less than zero.

d$.$ Rate is valid.