Which of the following operating systems is able to join a domain a) microsoft office pro b) microsoft surface r. t. c) google android d) ipad

The correct answer will be C. Google android.

Explanation:

Google android is a type of operating system based on open source software and modified version of Linux kernel. So it will really helps the system to join a domain. It will allow to expand or explore the network with authentication properly and obviously opens you to all the security.

The other three options doesn't have any relation with the domain :

Microsoft office (a software),

Microsoft surface R.T (a device) and

iPad (also a device)

So, option C is the correct answer.