Explanation:

CPU is the widely recognized and standard acronym for 'Central Processing Unit'. Option (c) 'Central processing unit' refers to the primary component of a computer that performs most of the processing tasks. Options (a) 'Cover processing unit' and (b) 'Control processing unit' are incorrect expansions of the acronym. Option (d) 'All' is incorrect as only (c) is correct. Option (e) 'None of these' is incorrect because (c) is the correct expansion.