computers are not nearly as powerful as supercomputers, but are capable of great processing speeds and data storage and occupy specially wired, air-conditioned rooms..

The correct answer is "Mainframe computer".  

Explanation:

The main objective of Mainframe computers it is used for critical applications by big organizations for the huge data processing like as corporate resource planning, and payment processing.

i want to say d but i could be wrong however it is organized if that could happen..

hope it could