Question

after the formation of the neural tube, the number of cells destined to become part of the adult nervous system
increases rapidly
quickly doubles and then declines
actually declines
stays the same until the end of the neural - groove phase
stays the same until the end of the neural - plate phase

Explanation:

During neural development, after the neural tube forms, there is a process of cell death (apoptosis) that occurs. Not all cells that were part of the initial neural - related cell population will survive to become part of the adult nervous system. This leads to a decline in the number of cells destined for the adult nervous system.

Answer:

actually declines