已知数列{an}满足an+1=
an2-2an+2
A.{a1|a1≥2017,a1∈N+}
B.{a1|a1≥2016,a1∈N+}
C.{a1|a1≥2015,a1∈N+}
D.{a1|a1≥2014,a1∈N+}