A Generative AI Engineer is developing a chatbot to help their company's internal HelpDesk Call Center team quickly find related tickets and provide resolutions. While creating the work breakdown tasks for this GenAI application, they are planning which data sources (either Unity Catalog volume or Delta table) to use. They have collected several candidate data sources for consideration:

• call_rep_history: A Delta table with primary keys representative_id and call_id. This table is used to calculate representatives' call resolution from the call_duration and call_start_time fields.
• transcript_volume: A Unity Catalog Volume containing all call recordings as *.wav files and their text transcripts as *.txt files.
• call_cust_history: A Delta table with primary keys customer_id and call_id. This table is used to calculate how much internal customers use the HelpDesk to ensure the chargeback model is consistent with actual service use.
• call_detail: A Delta table that includes a snapshot of all call details updated hourly. It contains root_cause and resolution fields, but these fields may be empty for calls that are still active.
• maintenance_schedule: A Delta table that lists both HelpDesk application outages and planned upcoming maintenance downtimes.

They need data sources that can add context to best identify ticket root cause and resolution.

Which TWO sources should they choose? (Choose two.)_