Step 1: Correlation Coefficient.
The correlation coefficient indicates the strength and direction of the relationship between two variables.
Its value always lies between -1 to +1. Hence A - III.
Step 2: Standard Deviation.
Standard deviation is considered the best measure of dispersion as it uses all data values.
Hence B - IV.
Step 3: Larger Samples.
Larger sample sizes give higher precision and more reliable estimates.
Hence C - I.
Step 4: Coefficient of Variation.
It is a relative and unitless measure of dispersion, used to compare variability across datasets.
Hence D - II.
Step 5: Conclusion.
So the correct matching is: A - III, B - IV, C - I, D - II.