As part of your summer research project, your professor has
asked you to perform comparative genomic hybridization (CGH). He
gives you DNA from one person who you know nothing about (referred
to as the test subject). You use this DNA as a template to make
green fluorescent DNA. You also make red fluorescent DNA with DNA
from a control person. When you perform CGH, you are surprised to
find that the ratio of green to red fluorescence is 2 along all of
chromosome 18. You conclude

A. the control person must be missing chromosome 18.

B. the test subject is likely to have cancer.

C. the test subject likely has Edward Syndrome.

D. the test subject likely has Down Syndrome.