In cells infected with simian sarcoma virus,the sis oncogene causes the cells to release increased amounts of Sis protein,which is recognized by PDGF-receptor molecules on the cells' surface.This type of signaling loop is an example of
A)Endocrine signaling. B)Paracrine signaling. C)Autocrine signaling. D)Trans-receptor signaling. E)None of the above.