In Bash, inserting “1>&2” after a command redirects

A.
standard error to standard input

B.
standard input to standard error

C.
standard output to standard error

D.
standard error to standard output

E.
standard output to standard input

Explanation/Reference:
A) 2>&1
B) does not make sense
D) 2>&1
E) use | (pipe) to redirect stdout to stdin