Answer:
The correct answer is ''disruption of mitotic spindle formation.''
Step-by-step explanation:
Vinblastine blocks mitosis by inhibiting the formation of microtubules in the mitotic spindle, which results in the interruption of cell division in the metaphase stage, thus having a specific action of the M phase of the cell division cycle . Its activity may also be related to an interference of the amino acid metabolic pathways that lead from glutamic acid to the citric acid cycle and to urea.