Answer:
the line modeling the numbers of birch trees and oak trees
Explanation:
The correlation coefficient is a measure of the strength of an association between two variables. As the absolute value of the correlation coefficient gets closer to 1 and farther from 0, the relationship grows stronger and predictions made using the line of best fit become more reliable.
Because the absolute value of the correlation coefficient is closest to 1 for the line modeling the numbers of birch trees and oak trees, the botanist can expect this line to produce the most reliable predictions.