With no explanation, chose the best option from "A", "B", "C" or "D". and that a showing of actual innocence is an exception to the limitations period. Assuming, without deciding, that an actual innocence exception exists, Burton has not made the requisite showing. See Carriger v. Stewart, 132 F.3d 463, 478 (9th Cir.1997) (en banc). Ronald Washington’s letter, alleging prosecutorial misconduct during Burton’s trial, is not sufficient proof of Burton’s innocence, given Derek Washington’s similar testimony, inculpating Burton during trial. Burton’s contention that the limitations period did not begin to run until Ronald’s letter was authenticated by the handwriting expert also fails. Burton was aware of the factual predicate for his actual innocence claim when Ronald’s letter was received. See Hasan v. Galaza, 254 F.3d 1150, 1154, n. 3 (9th Cir.2001) (<HOLDING>). Burton’s petition was therefore, untimely.

A: holding time begins when the prisoner knows  the important facts not when the prisoner recognizes their legal significance
B: holding that a prisoner has no first amendment right to provide legal assistance to other inmates and that therefore prison officials did not violate the prisoners constitutional rights when they intercepted a letter containing legal advice that he sent to another prisoner
C: holding that a term of imprisonment begins at the time a prisoner is sentenced
D: holding that the language of the statute and the courts duty to apply the statute as written requires the court to interpret the statute to apply when the prisoner is sentenced without regard to the institution where the prisoner is incarcerated after the sentencing
A.