The correct answer is: D. none of the mentioned.
FreeDrive is a cloud storage service that allows users to store files online and access them from anywhere. It does not allow users to view the content of others.
Facebook is a social networking service that allows users to connect with friends and family. It does allow users to view the content of others, such as posts, photos, and videos.
Twitter is a microblogging service that allows users to post short messages, called tweets. It does allow users to view the content of others, such as tweets, photos, and videos.
WhatsApp is a messaging app that allows users to send text messages, photos, and videos. It does not allow users to view the content of others.