BYOD (Bring your own device) is the correct answer. MITM is a type of attack. Embedded systems are systems that serve a specific purpose and are part of a larger system, thus this is not correct. iCloud is a storage/synchronization service offered by Apple.
Bring your own device (BYOD, /ˌbiː waɪ əʊ ˈdiː/)—also called bring your own technology (BYOT), bring your own phone (BYOP), and bring your own personal computer (BYOPC)—refers to being allowed to use one's personally owned device, rather than being required to use an officially provided device There are two major contexts in which this term is used One is in the mobile phone industry, where it refers to carriers allowing customers to activate their existing phone (or other cellular device) on the network, rather than being forced to buy a new device from the carrierThe other, and the main focus of this article, is in the workplace, where it refers to a policy of permitting employees to bring personally owned devices (laptops, tablets, smartphones, etc