A Collateralized Mortgage Obligation (CMO) principal balance is $1,000,000,000. The pass-thru rate is 5.35%. The Weighted Average Coupon rate is 6.35%. The weighted Average Months is 350. The PSA is 90. The CMO (at the time the CMO is first created) is divided into 4 tranches (A, B,C, D), each with a par value of $250,000,000 and a 5.35% coupon rate.

Within how many months from the creation of the CMO will tranche C principal be totally paid?

1. 30
2. 55
3. 207
4. 350