Unless officers establish to continue a detention during a pretextual stop, the stop must be ended, and must be established to pursue the investigation.

A. Probable cause - reasonable suspicion
B. Reasonable suspicion - probable cause
C. Consent - a warrant
D. A warrant - consent

During a pretextual stop, officers must first establish reasonable suspicion to continue the detention and then establish probable cause to further pursue the investigation. Reasonable suspicion allows for brief detentions, while probable cause is needed for searches, arrests, or obtaining warrants as laid out in Terry v. Ohio (1968).

Explanation:

During a pretextual stop, reasonable suspicion must be established by officers to justify the continuation of the detention. If they wish to pursue the investigation further, they must then establish probable cause. Hence, the correct answer is: b) Reasonable suspicion - probable cause.

Reasonable suspicion is a lower standard that allows police to briefly detain an individual and conduct a frisk if they believe the person is involved in criminal activity based on specific and articulable facts. Probable cause, on the other hand, is a higher standard requiring facts or evidence sufficient to warrant a belief by a reasonable person that a suspect has committed a crime. This standard is necessary for obtaining search warrants or making arrests without warrants in felony cases.

The landmark case Terry v. Ohio (1968) defined the boundaries of reasonable suspicion and continues to influence law enforcement protocols today. Without the necessary reasonable suspicion or probable cause, a stop must legally be ended, and the individual should be allowed to go.