If your answer was RAID-6, you are correct!
RAID-6: Dual parity. This level takes the striped parity region from RAID-5 and duplicates it. Each disk stripe has two parity regions, each calculated separately. The advantage of this level is that even if two disks fail, the RAID stripe would still have a complete set of data and be able to recover the failed disks. The biggest disadvantage is in performance. The performance impact of RAID-5 is roughly doubled as each set of parities is calculated separately. Where RAID-5 requires one extra disk for parity this level requires two, increasing the cost of the implementation.