Step 1: Understanding Tirthankaras.
In Jainism, a Tirthankara is a spiritual teacher who has achieved liberation and shows the path to others. Jain tradition recognizes 24 Tirthankaras.
Step 2: Identify the first Tirthankara.
The very first Tirthankara was Rishabhdeva (also known as Adinatha). He is considered the founder of Jain dharma traditions and mentioned in ancient Jain texts as well as some Hindu Puranas.
Step 3: Analyze each option.
- (A) Mahavira: 24th and last Tirthankara, not the first.
- (B) Parshvanatha: 23rd Tirthankara, earlier than Mahavira but not the first.
- (C) Ajitanatha: 2nd Tirthankara, not the first.
- (D) Rishabhdeva: Correct. He was the 1st Tirthankara.
Step 4: Conclusion.
The first Tirthankara of Jainism was Rishabhdeva.