Answer:
The correct option is C.
Explanation:
r-values represents correlation between two variables. The r-value lies from -1 to 1.
If r=-1 or close to -1, then it represents strong negative correlation.
If -1 < r < 0 or close to -0.5, then it represents weak negative correlation.
If r=0 or near to 0, then it represents no correlation.
If 0 < r < 1 or close to 0.5, then it represents weak positive correlation.
If r=1 or close to 1, then it represents strong positive correlation.
The given r values are -0.75, -0.55, -0.15 and -0.35.
From these r-values, -0.15 represents the weakest correlation because it is nearest to 0.
Therefore the correct option is C.