How to Select Specific Columns from a Data Frame in R

Which expression is correct to select the 3rd and 5th columns from a data frame called bats?

A. bats[c,(3,5)]

B. bats(c{3,5})

C. bats-x-c(3,5)

D. bats[c(3,5)]

Final answer:

The correct expression to select the 3rd and 5th columns from a data frame called bats in R is D. bats[c(3,5)].

To select the 3rd and 5th columns from a data frame called bats in R, the correct expression would be D. bats[c(3,5)]. This syntax uses the c() function to combine the column indices 3 and 5 into a vector, which is then used to subset the data frame bats for those specific columns.

Here's a step-by-step example:

1. Assume you have a data frame named bats which contains several columns.
2. To select the 3rd and 5th columns only, use the expression bats[, c(3, 5)]. Note the comma before the c() function which indicates you are selecting columns.
3. The result will be a new data frame with only columns 3 and 5 from the original bats data frame.