Answer:
B) quantities (which
Step-by-step explanation:
In the given passage/ sentence, the first mistake or error is in the incomplete use of the brackets, where the open bracket "(" is missing though the closed bracket ")" is used. And the second error is in the use of the comma/ pause after the word "quantities" which is not necessary or required.
Thus, the final and correct sentence with corrections will be
In large quantities (which one would expect to see when it is collected for an entire municipality), compost can be converted into a natural gas that can be used as fuel for transportation or heating and cooling systems.
Thus, the correct answer is option B.