What Did the Court Rule in Kyllo V

What did the Court rule in Kyllo v. United States (2001) when deciding on the use of a thermal imaging device by law enforcement officers to track the indoor cultivation of marijuana?

A) The use of the thermal imaging device to know the contents of the home was not a search because heat emanating from the house is located in open fields.
B) The use of the thermal imaging device to know the contents of the home was a search because the device was not available to the general public.
C) The use of the thermal imaging device to know the contents of the home was not a search because the defendants did not have any reasonable expectation of privacy in the heat.
D) All of the above.