A data analyst calculates the correlation coefficient (r) between advertising spend and sales revenue to be 0.80.

What does the coefficient of determination indicate in this context?

80% of the variation in sales revenue is explained by the variation in advertising spend.

64% of the variation in sales revenue is explained by the variation in advertising spend.

Sales revenue will increase by 64% for every $1 spent on advertising.

There is a 64% probability that advertising causes sales to increase.