I believe the correct answer is the last option. All of the choices are being regulated and influenced by the Auxins. These are hormones in plants that would cause the cells in the shoots to elongate and is responsible in plant growth.
I learned this long ago, I think it's either Mitosis or cell division, this is when one cell divides to make 2 cells and those 2 cell divide to make 4 cells and those 4 cells divide to make 8 cells and so on.
Centrioles produce spindle fibers.
Hope this helps! :)
Diluting an acid decreases the concentration of H+(aq) ions , which increases the pH level of the solution towards 7 , making it less acidic . However , the pH level of an acidic solution cannot become greater than 7 , because the water you add to dilute it is not alkaline .