THE_UNIT_THAT_PROVIDES_A_FOUR_LEVEL_PROTECTION_MECHANISM,_FOR_SYSTEM‚ÄÖ√Ñ√∂‚ÀÖ√Ë‚ÀÖ¬•S_CODE_AND_DATA_AGAINST_APPLICATION_PROGRAM_IS?$#

• A. central processing unit
• B. segmentation unit
• C. bus interface unit
• D. none of the mentioned