1. Acid and base are commonly used in industry on a large scale. For example, The steel industry uses hydrochloric acid to clean metal sheets before processing. On the other side of the pH scale, paper manufacturers make use of sodium hydroxide to remove lignin from paper pulp.
2. Both these are also important for the human body. Our kidneys and lungs work to maintain the acid-base balance. Acids are very lethal if not taken care of for the human body and causes like excessive skin problems, cramping, tooth decay, ligament problems, and even cancers.
3. The acid attack associated with a chemical change in the soil that can restrict the availability of essential plant nutrients and increase the availability of toxic elements. It is known as Soil acidity affects which totally affects the growth and nutritional values of crops.
4. All acid and base react with each other and resulting in a neutralization reaction by forming a salt and water like
HCl+NaOH→NaCl(salt)+H2O(water).
Thus all given options are correct.