What will be the output of the following R code?

> x <- list(a = 1:4, b = rnorm(10), c = rnorm(20, 1), d = rnorm(100, 5))
> sapply(x, mean)

A. if-else loop B. for loop C. while loop D. do-while loop

A. To execute a block of code if a condition is true, otherwise execute another block of code B. To create a loop that iterates a specified number of times C. To check multiple conditions sequentially D. To execute a block of code repeatedly until a condition is met

A. To toggle between TRUE and FALSE values B. To switch the positions of two elements C. To select one of several alternatives D. To change the direction of a loop

A. for (i in 1:10) { code_block } B. for (i = 1 to 10) { code_block } C. for (i = 1; i <= 10; i++) { code_block } D. for (i from 1 to 10) { code_block }