There are often not more than one or two independent variables tested in an experiment, otherwise it is difficult to determine the influence of each upon the final results. There may be several dependent variables, because manipulating the independent variable can influence many different things.
The bodies immune response includes all of those cells to help destroy pathogens that wish to bestow havoc on the beautiful homeostasis of the body.
The correct answer of the given question above would be option A. The purpose that the models served in ancient Egyptian and Chinese tomb is that, they were meant to make tombs more beautiful. These are wooden models which show ships, potters, servants and carpenters. Hope this answer helps.