#### Answer

$\text{
a function
}\\\text{Domain: } \{
2,3,5,11,17
\}\\\text{Range: }\{
1,7,20
\}$

#### Work Step by Step

$\bf{\text{Solution Outline:}}$
To determine if the given diagrams a function, check if the first components are all used only once.
The domain is the set of all first components, while the range is the set of all second components.
$\bf{\text{Solution Details:}}$
The first components in the given diagram are all being used only once. Hence, the given set is a function.
The domain is the set of all first components, while the range is the set of all second components. Hence, the given set of ordered pairs has the following characteristics:
\begin{array}{l}\require{cancel}
\text{
a function
}\\\text{Domain: } \{
2,3,5,11,17
\}\\\text{Range: }\{
1,7,20
\}
.\end{array}