Who says the following and why? "no one, no achaean labored hard as odysseus labored or achieved so much. and how did his struggles end? in suffering for that man; for me, in relentless, heartbreaking grief for him, lost and gone so long now—dead or alive, who knows? " *

It is said by Menelaus. He tells it to Telemachus because he returned from the war with Troy much earlier and Telemachus is Odysseus' son so it's important for him to know what relation the two men had and how sorry Menelaus is for what happened to Odysseus.

it supports the central idea which is the main cause of the authors writing or scripting it also affects it so that the people can get to know more about the particular book and makes us know about the central theme or climax