B. He turns up its nest with the plow.
In this passage the speaker says you, the mouse, saw the empty fields and with winter coming decided to make a home in them underneath the cold winds. Then crash! The plow blade cut through your house. In this passage the speaker is plowing his field to get it ready to lay fallow for winter when he turns out the mouse from it's house.
No one should put a seal on something that isn't theirs
