[单选题]
In radioactive dating, carbon-14 is o vtb3js5/smy thzr q3/d2nwnp-e0 : b8ften used. This nucleus emit he-2 qma44l c2vevgrc,do0kdj+9k/ ts a single beta particle when it decays. When this happens, the resulting nuc+dg hecc-t 9vl,o/r2 vjkd4m0k4 q2aeleus is
A. still carbon-14.
B. boron-14.
C. nitrogen-14.
D. carbon-15.
E. carbon-13.
