The seven sources of information on which an officer may rely in establishing probable cause to make a warrantless arrest are:

A. Hearsay, Officer's Observation, Informant's Tip, Circumstantial Evidence, Probable Cause, Reasonable Suspicion, Eyewitness Testimony

B. Probable Cause, Hearsay, Officer's Observation, Informant's Tip, Circumstantial Evidence, Reasonable Suspicion, Eyewitness Testimony

C. Officer's Observation, Hearsay, Informant's Tip, Circumstantial Evidence, Probable Cause, Reasonable Suspicion, Eyewitness Testimony

D. Informant's Tip, Circumstantial Evidence, Probable Cause, Officer's Observation, Hearsay, Reasonable Suspicion, Eyewitness Testimony

Officers can rely on seven key sources for establishing probable cause for a warrantless arrest: Officer's Observation, Hearsay, Informant's Tip, Circumstantial Evidence, Eyewitness Testimony, Reasonable Suspicion, and additional Probable Cause from investigative evidence.Hence option D is correct.

Explanation:

The seven sources of information on which an officer may rely in establishing probable cause to make a warrantless arrest are:

Officer's Observation
Hearsay
Informant's Tip
Circumstantial Evidence
Eyewitness Testimony
Reasonable Suspicion
Probable Cause derived from investigations and evidence

Probable cause is a legal standard for determining whether an arrest or search is constitutional. It is a lower threshold than the standard of proof required at a criminal trial.

The concept of reasonable suspicion, as defined by the Supreme Court in Terry v. Ohio (1968), is a lower standard than probable cause and allows police to stop and frisk individuals if there is reasonable suspicion of criminal activity. Arrest warrants, supported by probable cause and sworn affidavits, are also necessary to take individuals into custody, unless exigent circumstances apply.