Carbohydrates, fats, proteins: these organic molecules all have this element in common. this element can form multiple bonds, and it bonds with other elements as well as with itself.

good thing- during decomposition the organic molecules in organic matter are broken down into simpler organic molecules that require further decomposition or into mineralised nutrients

bad thing- it can be harmful in crop productivity

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.