Which equation represents a spontaneous transmutation

 The correct answer is:
37/20Ca --> 37/19K + 0/+1e

Explanation:
Transmutation, conversion of 1 element into another. A transmutation entails an amendment within the structure of atomic nuclei and thus is also induced by an action (q.v.), like nucleon capture, or occur ad libitum by decay, like disintegration and disintegration(qq.v.)