How Are ¹³C and ¹⁵N Different from the More Abundant

How are ¹³C and ¹⁵N different from the more abundant isotopes ¹²C and ¹⁴N?

A) ¹³C and ¹⁵N each have one more neutron than ¹²C and ¹⁴N
B) ¹³C and ¹⁵N each have one more proton than ¹²C and ¹⁴N.
C) ¹³C and ¹⁵N each have one less neutron than ¹²C and ¹⁴N,
D) ¹³C and ¹⁵N each have one less proton than ¹²C and ¹⁴N,,
E) ¹³C and ¹⁵N each have one less electron than ¹²C and ¹⁴N