Which of the Following Is/are an Example of Post-Translational Modification

Which of the following is/are an example of post-translational modification?

A) Digestive proteins are translated into inactive forms that can be activated at a later time and/or in a different place.
B) Chaperone proteins help newly translated proteins achieve the appropriate tertiary structure.
C) Proteins are modified by the replacement of one or more amino acids by sugars, which may then target the protein to a specific cell compartment.