The correct option is C haploid
The human gametes differ from all the other cells in the body because the somatic cells have a complete set of chromosomes i.e 46 chromosomes (diploid). But the gametes have only half the number of chromosomes i.e 23 chromosomes (haploid set). The gametes fuse during fertilisation to again result in a complete set of chromosomes. So, the correct option is 'haploid'.