HELP it’s due , I really need it

Technician a says after tire service work tires and wheels must be in a state of static and dynamic balance in order to avoid vibration in service. technician b says tires and wheels are balanced at the factory and do not need further balancing. who is correct?

Find a word that makes the both words

B. speculate about one positive way and one negative way that this boundary has affected the geographical units it separates over time.