You forgot to add to option (C) that during the course of negotiations, you were poisoned, beaten, robbed, Phantasmal Terrored, and finally sold into slavery in the Deep.
Grovel was the thin edge of the wedge.
The original Grovel was the "frightened goblin when you first enter and are given the choice to spare the goblin and even let him ride the lift up out of the Underdark".