honchos
That is restrictive in nature, it is not essential that it will refer to closest noun. SV agreement can be easily spotted. there should be some other solid reason why that is wrong. 1)you already said that THAT is restrictive in nature ==>therefore COMMA before THAT is the error.
2)moreover read my previous post i said "THAT refers to closest noun(
generally)"
generally means MORE LIKELY and not ALWAYS.
3)MOREOVER S-V agreement error i dont think is a LIQUID reason...thats a big error...
4)plus its good that you are trying to understand every reason but its also wastage of time breaking your head in wrong answers...
IMO above given reason are more than sufficient to eliminate that answer.
IF YOU CAN FIND MORE SOLID REASONS please share those.
REGARDS