To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) A picture that is downloaded from a computer outside the e-mail system when you open the message - This option is correct. Outlook may block pictures that are downloaded from external sources when you open the message to protect against potential security risks.
Option B) An attached photograph that appears inside a message - This option is incorrect. Outlook does not block attached photographs that appear inside a message by default.
Option C) An attached picture in an e-mail message from anyone not in your Contacts folder - This option is incorrect. Outlook does not block attached pictures in email messages based on whether the sender is in your Contacts folder or not.
Option D) None of these - This option is incorrect. Option A is correct.
The correct answer is Option A. This option is correct because Outlook may block pictures that are downloaded from external sources when you open the message to protect against potential security risks.