Which of the following mutations could be appropriately described as a position effect?
A. A point mutation at the -10 position in the promoter region prevents transcription.
B. A translocation places the coding sequence for a muscle-specific gene next to an enhancer that is turned on in nerve cells.
C. An inversion flips a gene from the long arm of chromosome 17 (which is euchromatic) to the short arm (which is heterochromatic).