Answer: C. Diabetes
During a routine blood test, a series of tests are carried out to detect the presence of foreign properties in the body, as well as identify them. In a routine blood test, chronic diseases can sometimes be identified easily, and one of such chronic diseases easily detectable in the bloodstream is diabetes.
Diabetes is marked by an abnormally high sugar level, and this sugar level can be easily measured in the blood.
Obesity is detected in a more thorough body examination, osteoporosis is detected in the bone, rather than the blood, and epilepsy is detected using an electroencephalogram (an EEG).