Beth accidentally clicked send on a message that was addressed to multiple recipients. she wants to use the recall option. which statement is true in regard to this scenario?

internal users that have not opened the message will still be able to open the message.
external users that have opened the message will be unable to access it again.
internal users that have opened the message will not be able to access the message again.
external users will be able to access the message.

External users will be able to access the message.

Explanation:

When dealing with the internal email system of an enterprise, it's possible to do a recall on the message.  If someone on the internal list didn't open the message yet, it will simply be deleted from his queue and it will appear as is that email never existed.

For external users, once the email has been sent, it cannot be recalled... so they'll be able to access it no matter what, because that email exists on an external server on which you have no management control.