Which of the following processes reduces cells originally classified as diploid to haploid?

Meiosis is the process that reduces cells originally classified as diploid (having a complete set of chromosomes) to haploid (having half the number of chromosomes). During meiosis, a single round of DNA replication is followed by two rounds of cell division, resulting in the formation of four genetically unique haploid cells. On the other hand, mitosis is a process of cell division that produces two identical diploid daughter cells, maintaining the same chromosome number as the parent cell. Therefore, neither mitosis nor both meiosis and mitosis reduce cells originally classified as diploid to haploid.