The map distance between genes A and B is 3 units, between B and C 10 units and between C and A 7 units. The order of the genes in a linkage map constructed on the above data would perhaps be
A B C
A C B
B C A
B A C
As we have already discussed in Gene Mapping
In the given question, Genes B and C would be at the extreme as they have a greater distance between them. Gene A would be in the middle position.
Hence, the correct answer is option d.