Which of the following commands will transform vector x<-c(1,2,3,4) into a 2x2 matrix in R? (There might be more than 1 answer)

1. (a) x <- matrix(x,ncol=2)
2. (b) dim(x) <-c(2,2)
3. (c) x <- matrix(x, 2*2)
4. (d) dim(x) <-[2,2]
5. (e) x <- matrix(x, diag=T)