If you have an existing package that doesn’t have an .Rproj file, you can use devtools for the use_rstudio(“_____/to/package”) to add it.
(a) Path
(b) Package
(c) Function
(d) Class
I got this question during an internship interview.
The origin of the question is Packages topic in chapter Commands, Packages, Visualizing Data and Linear Regression of R Programming