The secondary structure held together by hydrogen bonds is affected best describes the effect the chemical has on the structure of the protein. Therefore option B is correct.
What are hydrogen bonds?
Covalent bonds between amino acids are known to hold the main structure together; these bonds are unaffected by the chemical's presence.
An electronegative atom covalently bonded to a greater electronegative "donor" atom or group and another electronegative atom with a single pair of electrons the hydrogen bond acceptor—are attracted to each other through a purely electrostatic force.