Many of the Extrasolar Planets Discovered Thus Far Contain Large

Many of the extrasolar planets discovered thus far contain large planets orbiting close to their stars.It is considered unlikely to find habitable Earthlike planets in such systems.What is the reason?

A) Large planets close to their stars tend to block sunlight from reaching planets farther out in the "habitable zone."
B) The gravitational effects of these large planets would cause Earthlike planets to move into highly elliptical orbits, and that would result in large temperature variations.
C) Large planets close to their stars would tend to accumulate all of the heavy rocks and metals during the solar nebula phase. These would thus not be available for creating Earthlike planets farther out.
D) Large planets would tend to attract much space debris during the early formative phases of that solar system. This would result in other nearby planets being blasted and heavily cratered for long periods, making it difficult for a civilization to develop.