8.R You are trying to reproduce the results of the R labs, so you run the following command in R: > library(tree) As a response, you see the following error message: Error in library(tree) : there is no package called tree What went wrong?

a) You meant to use 'require(tree)'

b) You meant to use 'library("tree")'

c) The tree package is not installed on your computer

d) Nothing is wrong, that error message could not be produced by R