If You Wanted to Determine Whether Motor Neurons Are Already

If you wanted to determine whether motor neurons are already fated to innervate a particular target muscle before their axons exit the ventral root of the spinal cord, or if they just follow a path that leads them to the closest muscle in need of innervation, the best experimental design would be to

A) inject ephrins into a target muscle and track the axons that normally innervate that muscle.
B) use a Slit or Robo knockout model to track axonal growth.
C) remove a section of the spinal cord, place it somewhere else, and track the axonal growth.
D) remove a section of a muscle tissue, place it somewhere else, and track its innervation.