For the first question,
Alan has a degree of 4,
where as every other node in the network
has a degree of 2.
So Alan has the highest degree.
The shortest path between Sara and Lynn is 2 hops;
1 to Alan, than to Lynn.
The maximum shortest path between
any node in the network, that's asking what is
the maximum number of hops to get from
one node to any other node,
and you can see that to go through Alan here,
the maximum is 2.