PLEASE HELP ASAP If an individual has trisomy 21, what is true of the individual's chromosomes?

There are 21 chromosomes in each body cell.
There is a deletion of chromosome 21.
There are 47 chromosomes in each body cell.
There are 47 chromosomes in half the body cells.

The diagram below shows the layers of a rock having a trilobite: a rock column labeled rock is shown. the column has three layers. the bottommost layer of the rock has one shaded rhomboid shape, the middle layer has a rhombus with a diagonal along with two identical organisms marked as, trilobite, in the key, the top layer has two semicircles. a key is shown on the right side of the diagram. the shaded rhombus is marked as a, the rhombus with the diagonal is marked as b, the semicircle is marked as c which statement about the rock fossils is true?