Here, the important issue is data movement.
The records are huge, so exchanging or moving an entire record is expensive.
Bubble Sort and Insertion Sort can perform many exchanges or shifts.
For randomly ordered data, the number of exchanges can be quadratic.
Selection Sort is different.
It searches for the correct element using comparisons and performs only about one exchange per pass.
Thus, $\text{Number of exchanges}\approx N$
even though the number of comparisons is $\sim\frac{N^2}{2}$
Since the keys are tiny, comparing them is relatively cheap.
Since the records are huge, minimizing movement is much more important.
Selection Sort is best for this scenario because it avoids the large number of exchanges required by Insertion Sort and Bubble Sort.
Answer: B
