Which of the Following Are the Best Candidates to Search

Which of the following are the best candidates to search for planets that might harbor extraterrestrial life?

A) Halo stars, because planets can form in isolation from disruptive stellar encounters
B) Low mass stars (less than one-tenth of the mass of the Sun) , because these are the most common stars in our galaxy
C) Massive stars (greater than twice the mass of the Sun) because they provide more energy to promote biology
D) Solar-mass stars because they have both a large habitable zone and a long stellar lifetime.
E) Binary stars because they provide twice as much energy to promote biology