What is the test for a defense counsel to object to jury instructions at trial?

Where defense counsel fails to object to the jury instructions at trial, we review such instructions for plain error. See United States v. Taren-Palma, 997 F.2d 525, 531 (9th Cir.1993), cert. denied, --- U.S. ----, 114 S.Ct. 1648, 128 L.Ed.2d 368 (1994). "Plain error is 'highly prejudicial error affecting substantial rights[,] and is found only in exceptional circumstances.' " United States v. Varela, 993 F.2d 686, 688 (9th Cir.), cert. denied, --- U.S. ----, 114 S.Ct. 232, 126 L.Ed.2d 186 (1993), quoting United States v. Harris, 738 F.2d 1068, 1072 (9th Cir.1984). Hinton asserts that he objected to the district court's decision to give the jury a definition of murder and that the correct standard is therefore abuse of discretion. However, the record indicates that Hinton's objection was conditional and was waived upon defense counsel's indication that he accepted the court's proposed definition of murder. Accordingly, the plain error standard applies.