Which cytoskeleton protein a cell maintain its shape

There are three primary cytoskeletal proteins found in a cell, microtubules, actin and intermediate filaments.
Out of these three, microtubules contribute towards maintaining cell shape. Other functions performed by the microtubules such as the movement of secretory vesicles, organelles and macromolecule assemblies within the cell.

Ithink option a is correct because you cannot donate a different blood group than yours because it won't match.option a says betsy can donate to mark. they have the same blood group so donation can happen.