1. what is the proposed architecture goals and constraints
2. section on use-case view
3. section on logical view of proposed architecture
4. section on technical view of proposed architecture - This is most important section as you need to cover sub-sections like layers of architecture, each use-case realization with class & sequence diagrams, development view of project including package hierarchy. Also cover the mentioned NFRs in the assignment.
5. section on deployment view
6. Assumption & Risk - This section is also important as you will going to list doing complete assumption made while designing the system. Also list down the risk like unavailability of application etc.
7. Optional, but you can add Annexure (s) depending upon your sections
For part 3, you need to answer with respect to NFRs (performance, security, availability etc) mentioned in the assignment. Explain each question with points rather than big paragraph.