Compared with single sourcing, what is a key advantage to dual or multiple sourcing?

Explanation

The correct answers are 'it is easy to drive down costs' (as you can pit the suppliers against each other) and 'low risk of failure to supply' (if one supplier can't provide what you need, the other supplier might be able to).

Economies of scale and supplier loyalty are advantages of single-sourcing.

There is a risk of failure to supply is a risk associated with single sourcing.

There's a useful table of advantages and disadvantages of single / multi sourcing on p.22. Types of sourcing is a key topic for the exam.