In the following schematic drawing, a growing axon (in red) is extended to a target neuron to form three synapses. In its journey, it is guided by a variety of mechanisms. Sort the following mechanisms to reflect the order in which they guide the navigation of the growth cone toward the target neuron in this example. Ignore the final chemoattraction step toward the target neuron itself. Your answer would be a six-letter string composed of letters A to F only, e.g. FACBDE.

(A) Chemoattraction
(B) Chemorepulsion
(C) Cell surface adhesion
(D) Contact inhibition
(E) Extracellular matrix adhesion
(F) Guidance by pioneer neuron