At Universal Containers, the Account object has a Master-Detail relationship with an Invoice custom object. The app builder would like to change this to a lookup field, but is not able to do so. What could be causing this?

A. The Account is included in the workflow on the Invoice object.
B. The Invoice must have at least one Master-Detail field for reporting.
C. The Invoice records have existing values in the Account.
D. The Account record includes Invoice roll-up summary fields.

Suggest answer: D

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