The correct answer is option 4, "None of these".

Human ovum, also known as an egg cell, has a chromosome number of 23. This is because during the process of meiosis, which is involved in the formation of eggs and sperm, the number of chromosomes in the cell is halved. In humans, the usual number of chromosomes in each body cell (somatic cell) is 46, with 23 pairs. However, during meiosis, the ovum receives only one chromosome from each pair, resulting in a total of 23 chromosomes in the ovum. This is significant because when the ovum is fertilized by a sperm, which also brings 23 chromosomes, the resulting zygote will have a total of 46 chromosomes, the usual number in a human. Thus, it is important to note that the chromosome number in a human ovum is 23, not any of the options provided.