Answer:
The eldest oyster is more comfortable at home.
Step-by-step explanation:
My dude the eldest oyster doesn't seem to want to leave by the line, "Meaning to say he did not choose to leave the oyster bed". In this particular stanza, the walrus is not mentioned, so Option 2 and 4 is out of the question. Option 1 simply doesn't make sense in light of the passage. So, therefore, Option 3 is the way you should go.