What is produced in our muscles during the anaerobic respiratory phase?

Given below are two statements.
$Statement-I$ - Skeletal muscles usually derive energy by anaerobic respiration.
$Statement-II$ - After vigorous exercise,lactic acid accumulates in muscle fibres,leading to muscle fatigue.
In the light of the above statements,choose the most appropriate answer from the options given below:

In alcoholic fermentation,which of the following statements is correct regarding electron transfer?

Fermentation is an anaerobic respiration process. Which products are obtained in this process?

Which one of the following organisms may respire in the absence of oxygen?

Choose the correct option with respect to anaerobic respiration.