Cutting the same 8 kb piece with both enzymes together results in bands at 4.0, 2.5, 1.0, and 0.5. of the possible arrangements of the sites given below, which one is most likely?

Question options:  

Options are missing in the question statement. I have found them from another source. These are,

A) Y between 2 & 3, X between 4 & 5, and Y between 6 & 7.

B) Y between 2 & 3, X between 3 & 4, and Y between 7 & 8.

C) X between 3 & 4, Y between 4 & 5, and Y between 5 & 6.

D) Y between 2 & 3, Y between 3 & 4, X between 4 & 5.

E) Y between 0 & 1, X between 3 & 4, Y between 5 & 6.

The correct option is B

Explanation:

When a linear piece of viral DNA of 8 kb is cut with restriction enzymes (X and Y), there can be different arrangements of bands that depend on the enzyme's restriction sites. These bands can be seen on gel electrophoresis. Arrangments of the bands (4.0, 2.5, 1.0, and 0.5) can be possible if restriction enzymes (X and Y) cut between 2&3, 3&4, 7&8 kb(s). For further understanding, please see the attached photo.

if you know your abc's you should be able to get your answer or just use google