What Mechanism Explains the Presence of "Hot Jupiters" Around Many

What mechanism explains the presence of "hot Jupiters" around many other stars?

A) planetary migration caused by gravitational interactions between the planet and disk
B) evaporation of the disk by the stellar wind removes gas that was holding the planet at a large radius
C) rapid formation of the gas giant from evaporated rock and metal at the inner disk edge
D) gravitational attraction by terrestrial planets that formed at small radii attract the giant planets inward