The reason that certain spicy foods, such as the Habanero pepper, makes some people sweat is because they contain a chemical that stimulates the same nerve endings in the mouth as does a rise in temperature; this stimulation sometimes results in the activation of certain biological cooling mechanisms, one of which is perspiration.

The reason that certain spicy foods, such as the Habanero pepper, makes some people sweat is because they contain a chemical that stimulates the same nerve endings in the mouth as does a rise in temperature

The reason that certain spicy foods, such as the Habanero pepper, makes some people sweat is that these foods contain a chemical that stimulates the same nerves in the mouth like a rise in temperature

Certain spicy foods, such as the Habanero pepper, make some people sweat because they contain a chemical that stimulates the same nerves in the mouth like a rise in temperature does

The reason that certain spicy foods, such as the Habanero pepper, make some people sweat is that these foods contain a chemical that stimulates the same nerves in the mouth as does a rise in temperature

The reason that certain spicy foods, such as the Habanero pepper, make some people sweat is because they contain a chemical that stimulates the same nerves in the mouth as does a rise in temperature

OA is D.

What is the role of 'that'. It is not a relative clause here.

I am guessing you are convinced with the answer but just wondering about the role of THAT. If not, the REASON ..... is the main subject and is followed correctly by a singular verb IS (the REASON ...blah blah.. is that...). And, the plural verb MAKE refers to the plural subject (which is not the main subject) spicy foods. And finally the adverbial clauses should be compared with AS and not LIKE - "stimulates the same nerves as does rise in temperature".


THAT is functioning as an essential modifier of the noun CHEMICAL and as you said, THAT is indeed a RELATIVE PRONOUN.

MG-Gurus - Please let me know if I have gotten the technicalities of the post-mortem incorrect or correct :).

ManH Rocks!
- pH

That is acting as a 'subordinator'

over to MG-Gurus

"that" is definitely introducing a relative clause here. Take a closer look at the subjects and verbs at work here:

main S-V is "the reason ... is"

subordinate clause S-V is "foods ... make"

_________________
Tim Sanders
Manhattan GMAT Instructor