Law Enforcement Officers May Make Warrantless Observations into Constitutionally Protected

Law enforcement officers may make warrantless observations into constitutionally protected areas such a home or the curtilage without entering the constitutionally protected area.Which of the following is a true statement?

A) Any observation made cannot violate the reasonable expectation of privacy of the person whose premises or activities are being observed.
B) These plain view observations cannot independently provide the necessary probable cause to obtain a warrant.
C) These observations can be made from the open fields or a public vantage point, but not from the air.
D) These observations can be made from the public vantage point or from the air, but not from open fields.