Consider a system with 2 level caches. Access times of Level 1 cache, Level 2 cache, and main memory are 1 ns, 10 ns, and 500 ns, respectively. The hit rates of Level 1 and Level 2 caches are 0.8 and 0.9, respectively. What is the average access time of the system ignoring the search time within the cache?
1. 13.0 ns
2. 12.8 ns
3. 12.6 ns
4. 12.4 ns