[Solved] Matt Sampson asks your help in understanding the term "activity index." Explain the meaning and importance of this term for Matt. (b) State the two ways that variable costs may be defined. Chickenpox: A highly contagious viral infection causing an itchy, blister-like rash on the skin, primarily affecting children. Gastrointestinal Bleeding: Any form of hemorrhage occurring within the gastrointestinal tract, from the mouth to the rectum. Occult Blood: Blood that is present in such small quantities that it is not visible to the naked eye, often detected through medical testing. Liver Problems: A broad term that encompasses a range of conditions affecting the liver’s ability to function properly, such as hepatitis or cirrhosis.