[单选题]
When a proton passes thb: vcfuzavk; 520wg 1w l9on7grough matter, it is pos dc(fw xwi* .a5.)sgxbsible for it to interact with the matter in xaibgd (w )*.x.5cswfsuch a way that an electron and a positron are produced; this interaction is referred to as
A. the photoelectric effect.
B. the Compton effect.
C. pair production.
D. none of the given answers