Hashing

The keys 5, 28, 19, 15, 26, 33, 12, 17, 10 are inserted into a hash table using the hash function $h(k) = k \bmod 9$. The collisions are resolved by chaining. After all the keys are inserted, the length of the longest chain is __________. (*answer in integer*)

Which one of the following hash functions on integers will distribute keys most uniformly over 10 buckets numbered 0 to 9 for $i$ ranging from 0 to 2020?