The nurse should teach a patient to observe which side effects when taking ampicillin.

A. Macrophage: This is the correct answer. An activated monocyte is also known as a macrophage. Monocytes are white blood cells that can mature into macrophages when they move into tissues. Macrophages play a crucial role in the immune system by phagocytosing (engulfing and digesting) pathogens and cellular debris.

B. Lymphocyte: Lymphocytes are another type of white blood cell that plays a central role in the immune system. They include B cells, T cells, and natural killer cells. Lymphocytes are primarily involved in adaptive immune responses, such as antibody production (B cells) and cell-mediated immune responses (T cells).

C. Plasma Cell: Plasma cells are a type of B cell that produces antibodies (immunoglobulins). They are involved in the adaptive immune response, specifically in the production of antibodies that target specific pathogens.

D. Polymorphonuclear Leukocyte: This term typically refers to a group of white blood cells that have a multi-lobed nucleus. Neutrophils, eosinophils, and basophils are examples of polymorphonuclear leukocytes. They are involved in innate immune responses, including the phagocytosis of pathogens.

A. "Cephalosporins are assigned to generations based on their relative costs to administer."
This statement is incorrect. The classification of cephalosporins into generations is based on their antimicrobial spectrum and activity against specific bacteria, not their cost.

B. "Later generations of cephalosporins have lower resistance to destruction by beta-lactamases."
This statement is not accurate. In fact, later generations of cephalosporins have increased resistance to destruction by beta-lactamases, which are enzymes produced by bacteria that can break down certain antibiotics.

C. "Cephalosporins have increased activity against gram-negative bacteria with each new generation."
This statement is correct. Cephalosporins are grouped into generations (first to fifth) based on their antibacterial spectrum. As the generations progress, there is an increase in activity against gram-negative bacteria, among other improvements in their spectrum.

D. "First-generation cephalosporins have better penetration of the cerebrospinal fluid."
This statement is generally true. First-generation cephalosporins have better penetration into the cerebrospinal fluid, making them useful for treating certain central nervous system infections.