DNA is an identifier, I'm not exactly sure how to answer this.
It is B, since it is at the end of the investigation
43)A 42)D bhhhhhhhhhhhhhhhhhhhhh
Since domestic cats reproduce through meiosis, each parent gives off half of their genetic code (or DNA) to their offspring. The answer would be B, 19 chromosomes because that is half of 38. That is why when a parent gives birth to their child, they don't look exactly the same or act exactly the same as either of their parents. They are a mix of both, which is another explanation for why no two people look exactly alike.
You may wonder, a domestic cat births more than one offspring at a time. If multiple offspring share the same parents, why don't they look the same? The reason for that is because the half DNA that the parent is giving off is a different half than they gave to another offspring, if that makes any sense.
Hope that helped you! :)