Q. Point out the correct statement?

• (A) "by.total" first subtracts out time spent in functions above the current function in the call stack
• (B) The summaryRprof() function calculates how much time is spend in which function
• (C) By default, the profiler samples the function call stack every 0.02 seconds
• (D) The Rprofiler() function starts the profiler in R