Biometrics is a comprehensive high-tech discipline technology, which closely combines computer technology, optical technology, acoustic technology, biometrics technology, etc., and makes use of the inherent characteristics of human biology (fingerprints, retinas, palm prints, etc.) and behavioral characteristics (voices, handwriting, etc.) to identify the identity of individuals. Accompanied by the development of big data and Internet of Things and other technologies, biometrics is more widely used in the field of financial payments. Mobile payment collar city, on the basis of the security of static physical characteristics, can be achieved through behavioral biometrics for further verification. So the answer is B.