Need more explain on this TOEFL® question!

[Chantha.Him]

Hello all:

It's my first time to raise this question after I have read a wondering question and provided answer.
The question:

In the preparation of fibrous material for production uses, stiff wooly fibers from plant_____fibers from animal sources.
a) the most heat the
b) need more heat than
c) than more heat needed
d) need the more heat than

So what is your answer? a, b, c, or d?
For me, I chose answer b) need more heat than; is it right?

The answer sheet says NO,
the correct one is d) need the more heat than;

So anyone could explain about this???
I wondering,,,,,

[Kitosdad]

D is wrong and B is correct. EOS.
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If you need me, I'm here.

[Chantha.Him]

Hi Kitosdad:

Thank for your answer,
but could you give more explanation?

[Kitosdad]

Good morning Chantha.Him, the definite article " the " is not required in this instance.
_________________
If you need me, I'm here.