During prometaphase, the microtubules of the mitotic spindle attach only to the kinetochore of a single sister chromatid and not to the other for the maternal copy of chromosome 21. what will happen to the copy number of chromosome 21 in the resulting daughter cells?

a. one of the daughter cells is missing both copies of chromosome 21 and the other cell has four copies of chromosome 21.

b. both daughter cells have double the normal number of chromosome 21 (four copies each).

c. one of the daughter cells has trisomy (three copies) of chromosome 21 and the other daughter cell is missing one of the two copies of chromosome 21.