Final answer:
In the 15th-century, a Christian tributary prince to the Ottomans was obligated to collect taxes, provide troops, and had the option of converting to Islam.
Step-by-step explanation:
In the 15th-century, a Christian tributary prince to the Ottomans had several obligations:
- Collecting taxes for the Ottomans: They were responsible for gathering and delivering taxes from their subjects to the Ottomans.
- Providing troops for Ottoman campaigns: They were also expected to supply soldiers to the Ottoman army when required.
- Converting to Islam: Although not mandatory, many Christian princes converted to Islam as a sign of loyalty to the Ottomans.
Therefore, the correct answer to your question is a) Collecting taxes for the Ottomans, b) Providing troops for Ottoman campaigns, and c) Converting to Islam.