The correct option is
A One half of chromosome
1) A chromatid is one-half of two identical copies of a replicated chromosome. During cell division, the identical copies are joined together at centromere. Joined chromatids are known as sister chromatids. Once the joined sister chromatids separate from one another in anaphase of mitosis, each is known as a daughter chromosome.
2) In gamete cells, the cell contains half the number of chromosomes as body cells, are called Haploid chromosomes.
3) Body cells such as muscle,skinblood etc. These cells contains a complete set of chromosomes (46 in humans),are called Diploid or complete chromosomes.
So, the correct answer is 'One half of chromosome'.