With no explanation, chose the best option from "A", "B", "C" or "D". shall forthwith be mailed to all parties. Within ten days after being served with a copy, any party may serve and file written objections to such proposed findings and recommendations as provided by rules of court. A judge of the court shall make a de novo determination of those portions of the report or specified proposed findings or recommendations to which objection is made. 28 U.S.C. § 636(b)(1)(C). “A party ‘may file objections within ten days or he may not, as he chooses, but he ‘shall’ do so if he wishes further consideration”. Negron v. Cir.1993) (stating that “[o]bjeetion to a magistrate’s report preserves only those objections that are specified”); Keating v. Secretary of H.H.S., 848 F.2d 271, 275 (1st Cir.1988); Borden v. Secretary of H.H.S., 836 F.2d 4, 6 (1st Cir.1987) (<HOLDING>). See generally United States v.

A: recognizing de novo standard of review
B: holding that we review constitutional challenges de novo
C: holding that appellant was entitled to a de novo review however he was not entitled to a de novo review of an argument never raised
D: holding that review of the construction of a sentencing statute is de novo
C.