What experimental technique or instrumentation was used to determine kinesin step size?

Optical trapping interferometry

Explanation:

Optical trap is a device which can measure forces or dielectric objects of magnitude of Pico newton or micron.  

In this,  a high focused light beam is used to view objects under the  microscope. It is highly used in molecular and cell biology and biophysics

This methodology has been adapted to sort lipids at cell surface and in activation of kinase in the dendritic cells

i would go with b

cytokinesis occurs after telophase so that eliminates d

and the entire reason for cytokinesis is for cellular reproduction

it's the cell cycle, but cytokines is when the cell divides.

theres 3 stages interphase,mitosis,and cytokines.

interphase prepares the cell for division.

mitosis is the process of dividing the cell,it has 4 parts interphase,anaphase,metaphase,and telophase.

lastly there's cytokines,that's when the cell divides into 2 daughter cells