A researcher is trying to produce a new cancer drug to be tested on small tumors. The tumor has to be localized in a small area of the body and cannot have metastasized (spread to other areas of the body). Furthermore, this drug must prohibit the signaling from one tumor cell to another tumor cell. Given the above information, this new drug will prohibit
A. direct physical contact between tumor cells.
B. autocrine signaling between tumor cells.
C. paracrine signaling between tumor cells.
D. endocrine signalizing between tumor cells.
Answer: C