Option C — 46
A human zygote is formed by fusion of a sperm (23 chromosomes) and an egg (23 chromosomes), giving the zygote 46 chromosomes.
Each human gamete (sperm/egg) is haploid — it carries 23 chromosomes. Fertilisation combines two gametes, restoring the diploid number of 46. Option A (23) is the gamete number; Option D (92) would be if a zygote fused again; Option B (44) is incorrect. Examiners expect you to recall that human body cells have 46 chromosomes, so the zygote must also have 46.