Which of the following terms refers to a group of symptoms that consistently occur together?

The term that refers to a group of symptoms that consistently occur together is "syndrome." In medical terminology, a syndrome is a set of signs and symptoms that frequently occur together and characterize a particular abnormality or condition. For instance, in the context of health, conditions such as Down syndrome or irritable bowel syndrome illustrate how specific symptoms are linked to distinct medical diagnoses.

The other terms listed do not pertain to the grouping of symptoms. "Scheme" typically refers to a structured plan or program, often with a connotation of deceit. "Deride" means to express contempt or ridicule, which has no relation to medical terminology. "Drudgery" describes hard, menial, or dull work, rather than a medical or symptomatic context. Thus, "syndrome" is the appropriate choice in the context of symptoms occurring together.