10. A tracer is a radioactive element whose pathway through which a chemical reaction can be followed. Tracers are commonly used in the medical field and in the study of plants and animals. Radioactive Iodine-131(I131) can be used to study the function of the _____ gland assisting in detecting disease.
a. Adrenal
b. Salivary
c. Pituitary
d. Thyroid