Mongodb Set 3

By using id field implicitly ✘ By using id field explicitly ✘ Both of these ✘ None of these ✔

The documents of a collection needs to have a unique set of fields. ✘ The collections can be created without defining the structure. ✘ It supports multi-document transactions. ✘ The structure of a document can be changed by adding or deleting fields. ✔