Without the answer options I cannot tell you the answer exactly, however X linked disorders are found only on X chromosomes and are indicated by a lowercase letter next to the X. Xr would be an example of the notation. A male has one X chromosome and one Y chromosome, where females have two X chromosomes.
The allele combination of a male with an x linked recessive disorder would look something like XrY.
The answer has to be option B "testable." A hypothesis is a educated guess on what you think is going to happen during a experiment. Also its not going to be option A because a hypothesis doesn't exactly have to be written homeschool students have there instructions on a computer in order to be completed. Its not option C because a hypothesis has the have its test variables. (independent & dependent variables) Its also not option D because some scientists conduct their experiments by themselves.
Hope this helps!
That the property of all living things are made of many cells
