You can use this dna fingerprinting information to make a judgment about maternity because

The full question goes like this :
Molecular biologists have perfected DNA fingerprinting so that it is possible to use the technique to provide evidence to solve crimes and even identify a child's parents. Recently, a U.S. immigrant asked the U.S. Citizenship and Immigration Services for permission to have her young daughter who was living with grandparents in their homeland join her.Her request was denied because there was an apparent mix-up with the child's birth certificate and it could not be used as proof of maternity. Proof is required in cases such as this. The mother requested DNA fingerprinting to make her case. Samples of DNA were taken from the mother (Mom) and daughter (D1) as well as from another daughter (D2) and a son (S) living in the United States with her. Tandem repeat analysis was run on the four samples, and the results are shown here

You can use this DNA fingerprinting information to make a judgment about maternity because .

The correct answer is because of the specific DNA band on the electrophoresis gell.
What does this actually mean?
The forensics take DNA samples from the mother and her children. They multiply a specific region of the DNA that is variable and they run these DNA segments through an electrophoresis gell. The bands on the gell of the same position can be identified and used as proof of maternity.
When the scientists observe the bands and find the identical bands in the child and the mother, this can bee a proof of maternity.