Certain statements are made regarding tetrapod limb development.

A. During vertebrate limb development, Apical Ectodermal Ridge (AER), forms at the dorso ventral ectodermal boundary at the distal tip of the developing limb bud.

B. The proximal-distal growth and differentiation of the tetrapod limb bud are made possible by a series of interactions between the apical ectodermal ridge (AER) and limb bud mesenchyme directly beneath it.

C. During wing development in chick, if the Apical Ectodermal Ridge (AER) is removed, the limb development ceases.

D. Placing leg mesenchyme directly beneath the wing AER, distal hindlimb structures develop at the end of the wing, and if replaced by non-limb mesenchyme sheath AER, the AER does not regress.

E. During wing development in chick, if the Apical Ectodermal Ridge (AER) is removed, the limb development continues.

Choose the correct combination of statements below.