In which of the following cells are active lysosomes found?

Active lysosomes are typically found in cells that require a high level of intracellular digestion, such as white blood cells. This is because white blood cells must digest more material than most other types of cells in their quest to battle bacteria, viruses, and other foreign intruders. 

Therefore, the correct answer to the question is white blood cells. However, lysosomes are also active in other cells such as intestinal cells, skin cells, and liver cells, among others, depending on their function and requirements for intracellular digestion and waste removal.