Part B - what if you have multiple primary beneficiaries?
If you have multiple primary beneficiaries, and none of them survives you, then the money goes to the contingent beneficiaries.
Now a complication - if your life insurance policy has multiple primary beneficiaries, and one of them predeceases you or dies along with you, should that primary beneficiary's share go to the remaining primary beneficiaries, the contingent beneficiaries, or the person's children?
The answer is, you can add descriptions to your beneficiary designation to take care of such situations based on whatever your desire.
Part C - do I need to name contingent beneficiaries?