The correlation coefficient of a scatter plot with line of best fit shown will be the slope of the line.
We can eliminate last 2 choices because the line is clearly a downward sloping line and it's slope wont be positive.
From the first two, it looks like the plot's slope is very close to -1. So we take -0.91, instead of -0.35. [note: 0.91 is more steeper than 0.35 (which is very relaxed)]
ANSWER: -0.91