Correct option is B
Explanation-
Retinoic acid (RA) is known to respecify the positional identity of blastema cells during limb regeneration in amphibians like newts. Specifically - RA causes distal blastema cells to adopt a more proximal identity. This means if a newt's limb is amputated and RA is applied to the regenerating blastema, the cells will regenerate structures that are normally closer to the body (more proximal) rather than the structures they originally belonged to (more distal). This phenomenon illustrates the role of RA in proximalization of positional information.
Incorrect Options -
Option a - RA will have no effect – RA has a strong effect on positional identity.
Option c - The cells will become respecified to more distal position – RA causes a shift to proximal, not distal identity.
Option d - Cells will lose their positional information and remain dedifferentiated – RA does not erase positional information; it alters/resets it to a more proximal fate.
Final Answer: Option b – "The cells will become respecified to more proximal position."
