Which of the Following Statements About Carbon Migrations Is (Are)correct

Multiple Choice

Which of the following statements about carbon migrations is (are) correct?

A) Carbon migrations never occur by a sigmatropic rearrangement.
B) Under thermal conditions, a [1,3] carbon migration that occurs suprafacially must also occur with inversion of configuration at the migrating carbon.
C) Under thermal conditions, a [1,5] carbon migration that occurs suprafacially must also occur with inversion of configuration at the migrating carbon.
D) Under thermal conditions, a carbon migration that occurs suprafacially must occur with inversion no matter the system's symmetry.
E) B, C, and D