With no explanation, chose the best option from "A", "B", "C" or "D". standard. Id.; see also State v. Ray, 659 N.W.2d 736, 742 (Minn.2003). We take this opportunity to articulate an appropriate standard of review of a district court’s ruling on whether police properly clarified an equivocal request for counsel. We will review de novo the application of the “stop and clarify” rule from State v. Robinson, 427 N.W.2d 217, 223 (Minn.1988), but defer to any factual findings by the district court that are not clearly erroneous. We first consider whether appellant unequivocally invoked his right to counsel. It is a violation of the U.S. Constitution for investigators to continue a custodial interrogation after a suspect has unambiguously requested the assistance of counsel. See Davis v. United States, 512 U.S. 452, 459, 114 S.Ct. 2350, 129 L.Ed.2d 362 (1994) (<HOLDING>); see also State v. Munson, 594 N.W.2d 128, 139

A: holding that a suspect must unambiguously request counsel
B: holding that the interrogation must cease once the suspect invokes his miranda right to counsel
C: holding suspect must unambiguously request counsel before applying rule established in edwards that police questioning must cease once suspect requests counsel during interview
D: holding that interrogation must cease if the suspect unambiguously asserts his right to counsel
D.