Which Statement About Extrasolar Planets Found to Date Is True

Multiple Choice

Which statement about extrasolar planets found to date is true?

A) All lie more than 2 AU from their star.
B) Some are so close to their stars that their periods are just a few days.
C) Few are found by Doppler shifts of their stars, due to their gravity.
D) Most have orbital periods of more than a year.
E) All are terrestrials, comparable in size to Earth.