Which passage from grendel best illustrates the theme "life is meaningless"?

After a thorough research, there exists a question that has the following choices.a) all order, i've come to understand, is theoretical, unreal -- a harmless, sensible, smiling mask men slide between the two great, dark realities.  b) i seize up a sleeping man, tear at him hungrily, bite through his bone-locks and suck  hot, slippery blood.c) fate often enough will spare a man if his courage holds. (162)d) as if casually, in plain sight of them all, i bit his head off, crunched through the helmet and skull with my teeth and, blood-slippery body in two hands. (79)the correct answer is letter  a) all order, i've come to understand, is theoretical, unreal -- a harmless, sensible, smiling mask men slide between the two great, dark realities. 

The answer is most likely d