A swapping system eliminates holes by compaction. Assuming a random distribution of many holes and many data segments and a time to read or write a 32-bit memory word of 4 nsec, about how long does it take to compact 4 GB? For simplicity, assume that word 0 is part of a hole and that the highest word in memory contains valid data.

The compaction time is 8192 s

Explanation:

Compaction time = (read + write) × Memory address.

Compaction time = 2 × 4⁻⁹s × Memory address

Memory address can be estimated as follows:

given;

data size = 4 GB = (4 x 2³⁰) bytes

memory = 32-bit  = 4 bytes

Memory address

Compaction time = 2 × 4⁻⁹s ×2³⁰

Therefore, the compaction time is 8192 s

i think the answer is a or d