An after trigger on the Account object performs a DML update operation on all of the child Opportunities of an Account. There are no active triggers on the Opportunity object, yet a "maximum trigger depth exceeded" error occurs in certain situations. Which two reasons could posssibly explain the Account trigger firing recursively?A. Changes are being made to the account during criteria based sharing evaluationB. Changes are being made to the account during an unrelated parallel save operationC. Changes to opportunities are causing cross-object workflow field updates to be made on the accountD. Changes to opportunities are causing roll-up summary fields to update on the account