Read the scenario below and answer the question that follow.

An automotive manufacturer, Toyota is planning to launch a new line of electric vehicles $($EVs$)$ to meet growing demand. They need to select suppliers for EV batteries, electric motors, and other components. They are considering purchasing large volumes and due to the nature of an assembly line they need to ensure disruptions are kept to a minimum.

Q$\mathrm{.}3\mathrm{.}1$ Identify whether Toyota should use a single supplier or multiple suppliers for EV batteries. Justify your answer.

Q$\mathrm{.}3\mathrm{.}2$ When deciding on a supplier there is a checklist that Toyota will need to use to ensure they evaluate the suitability of their supplier. Discuss four key factors that Toyota will need to consider when selecting a supplier.