The statement Bonds in the hydrogen peroxide are weakened in catalase's active site, allowing the chemical reaction to occur is the answer. Catalase is an enzyme in the liver that breaks down harmful hydrogen peroxide into oxygen and water.
Water can act as either a base or an acid. Water acts as an acid by donating a hydrogen ion when it reacts with a stronger base such as sodium hydroxide. Water may also act as a base when it accepts hydrogen ion when reacting with a strong acid such as hydrochloric acid. This is based on Bronsted concept and definition of a base ( proton acceptor) and acid (proton donor). Such a compound that can act as a base and as an acid is called an amphiprotic molecule.
I believe it’s C because the heart pumps blood through the body