Directions: Select the option that best replaces the underlined phrase in the sentence to make it grammatically correct. If the original sentence is already correct, select "No improvement required".

The senior accountant assisted our team to pay up a significant portion from liabilities accumulated during the factory expansion.

The correct option is to pay off a significant portion of.

Detailed Explanation:
The original phrase "to pay up a significant portion from" contains two grammatical issues related to phrasal verbs and preposition usage:

1. Phrasal Verb Error:
The phrasal verb "pay off" means to settle, discharge, or clear a debt or liability. On the other hand, "pay up" means to pay money reluctantly or under pressure. In the context of business debts/liabilities accumulated during expansion, "pay off" is the appropriate phrase.

2. Preposition Error:
When referring to a part or fraction of a whole, the noun phrase takes the preposition "of" (e.g., "a portion of", "a part of"). Using "from" after "portion" is grammatically incorrect here.

Combining these two corrections, the phrase becomes "to pay off a significant portion of".

Corrected Sentence:
"The senior accountant assisted our team to pay off a significant portion of liabilities accumulated during the factory expansion."