Which of the following statements concerning supply chain risk is true?

Which of the following statements concerning supply chain risk is true?

1. Most companies have a clear understanding of how resilient their supply chains are to failure.

2. Both the chances of disruption occurrence and magnitude of loss must be considered.

3. Focusing attention on the 20% of suppliers that incur 80% of the cost is a recommended approach.

4. All of the above are true.