Match List I with List II. List I: (a) Isolated I/O, (b) Memory-mapped I/O, (c) I/O interface, (d) Asynchronous data transfer. List II: (i) Same set of control signals for I/O and memory communication, (ii) Separate instructions for I/O and memory communication, (iii) Requires control signals between the communicating units, (iv) Resolves the differences between the central computer and peripherals.

1. A(a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)
2. B(a)-(i), (b)-(ii), (c)-(iii), (d)-(iv)
3. C(a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)
4. D(a)-(i), (b)-(ii), (c)-(iv), (d)-(iii)

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Correct answer: C. (a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)

Explanation

Isolated I/O has separate I/O instructions; memory-mapped I/O shares memory's control signals; an interface bridges CPU and peripheral differences; asynchronous transfer needs control signals between units.