The diagram illustrates several stages of cell division in a fruit fly. Cell X contains 8 chromosomes. How many chromosomes are present in cell Y and in cell Z?
- Acell Y: $4$, cell Z: $4$
- Bcell Y: $4$, cell Z: $8$
- Ccell Y: $8$, cell Z: $4$
- Dcell Y: $8$, cell Z: $8$