Halcyon, an e$-$publisher, has recently decided to use an information system that administers the way its customers access its online publications. The system assigns each customer with a unique ID$,$ maintains records of the books purchased by them, encrypts electronic documents for transmission, and includes options to order hard copies of the electronic documents they read online. Which of the following refers to the set of technologies used in this case?

online identity management $($OIM$)$

digital rights management $($DRM$)$

Internet resource management $($IRM$)$

inventory management $($IM$)$