#### Answer

$a.\quad\{0,4,7,8\}$
$b.\quad\{0,4,7,8\}$
$ c.\quad$Function.

#### Work Step by Step

When the correspondence is defined as a set of ordered pairs,
the first coordinate represents a member of the domain,
the second represents the corresponding member of the range.
$ a.\quad$
Domain = set of first coordinates,
$\{0,4,7,8\}$
$ b.\quad$
Range = set of second coordinates
$\{0,4,7,8\}$
$ c.\quad$
For the correspondence to be a function,
there must not be two ordered pairs with the same first coordinate (and different second coordinates)
This is because EACH member of the domain corresponds to EXACTLY ONE member of the range.
No multiple pairs with the same first coordinate.
This is a function.