If the Map Distance Between Genes a and B Is

Multiple Choice

If the map distance between genes A and B is 20 map units and the map distance between genes B and C is 35 map units, what is the map distance between genes A and C?

A) 15 map units
B) 55 map units
C) More information is needed to distinguish between 15 and 55 map units.
D) Gene C must be located on a different nonhomologous chromosome.