Sister chromatids are:

Explanation

This question is asking about sister chromatids. Sister chromatids are two identical copies of a single chromosome that are produced during the S-phase of the cell cycle. During this phase, the DNA in the cell is replicated, resulting in two identical copies of each chromosome. These two copies are called sister chromatids. Option A is the correct answer because it accurately describes sister chromatids. Option B is incorrect because pairs of chromosomes refer to homologous chromosomes, which are not identical. Option C is incorrect because the points of attachment of centromeres to the chromosomes are called kinetochores. Option D is also incorrect because chromosomes found in cells of sisters is not a scientific term. It is important to understand the structure of chromosomes and their duplication during the cell cycle. This knowledge is important in understanding genetics and inheritance. To learn more about this, please read the relevant sections of the recommended textbooks