Which of the following is not related to multiple fission?

The correct answer is "Asexual reproduction in which many daughter cells are not produced."

Multiple fission is a type of asexual reproduction where a single cell divides multiple times to produce many daughter cells. 

Therefore, options "Asexual reproduction in which many daughter cells are produced", "The nucleus is repeatedly divided to generate a large number of nuclei", and "Plasmodium undergoes multiple fission" are related to multiple fission. 

Option "Asexual reproduction in which many daughter cells are not produced" is the opposite and not related to multiple fission since it implies that no daughter cells are produced during asexual reproduction.