Point out the correct statement?
(a) update_element update contents of a theme
(b) Use theme_update_element to modify a small number of elements of the current theme or use theme_set to completely override it
(c) theme_bw is theme with grey background and white gridlines
(d) is.rel reports whether x is a theme object
I had been asked this question in examination.
My doubt is from ggplot2 in section Profiling, Simulation and Data Analysis of R Programming