Which of the following is true about the inference rules for FDs$?$

Question $1$ options:

They cannot be used to infer new FDs from a set of existing FDs

They can only be used to infer FDs in certain legal relation states of R

They can be used to infer additional FDs that hold whenever the FDs in F hold

They can be used to infer additional FDs that contradict the FDs in F$.$