All Possible Combinations of Values in a Vector R

Question

In R, I have the following list of letters:

lets <- c("A", "B", "C")

I want to be able to return a resulting list of lists that includes every possible combination of the letters, which would look like the following:

[[1]]
[1] "A"

[[2]]
[1] "B"

[[3]]
[1] "C"

[[4]]
[1] "A" "B"

[[5]]
[1] "A" "C"

[[6]]
[1] "B" "C"

[[7]]
[1] "A" "B" "C"