Question

Under anaerobic conditions, pyruvate can be broken down by ____________.

Answer 1

Under anaerobic conditions, pyruvate can be broken down by  Fermentation

Under anaerobic conditions, there will be no oxygen left within the cell, When this happen,  pyruvate will be converted into some form of lactic acid.
This type of substance could be converted into a form of alcohol, so it could be considered as a fermentation process.