Primary and secondary memory – UGC NET Question

Statements A, B and C correctly distinguish between primary and secondary memory, while statement D is false. RAM is volatile and loses data when power is off, ROM is non-volatile and stores firmware, and hard disks and SSDs are secondary storage devices. Primary memory by definition does not retain information permanently without power, so D cannot be accepted. Thus, the combination A, B and C only is correct.

Option A:
Option A is correct because it includes the three accurate statements and excludes the incorrect one. It reflects the standard classification of memory in computer architecture, showing temporary RAM, non-volatile ROM and external secondary storage.

Option B:
Option B is incorrect because it lists only A and B as correct, omitting C. While A and B are true, recognising hard disks and SSDs as secondary memory is also essential. Leaving out C makes the explanation incomplete.

Option C:
Option C is incorrect because it groups B, C and D as correct statements. Statement D contradicts the concept of primary memory as volatile, so its inclusion invalidates the combination even though B and C are true.

Option D:
Option D is incorrect because it assumes all four statements are correct and therefore accepts D. Since D conflicts with the volatile nature of primary memory, the entire set cannot be considered correct.