The question asks us to identify the person who was not a Jain Acharya. Let`s analyze each option:

1. Bhadrabahu: Bhadrabahu was a renowned Jain Acharya who lived around 300 BCE. He was a prominent figure in the Jain community and is known for his contributions to Jain literature.

2. Khema: The correct answer is option 2. Khema was not a Jain Acharya. There isn`t much information available about Khema, and he does not appear in the list of prominent Jain Acharyas.

3. Haribhadra: Haribhadra was a well-known Jain Acharya who lived around the 8th century CE. He was a prolific writer and composed numerous treatises on Jain philosophy and ethics.

4. Siddhasena Divakara: Siddhasena Divakara was a prominent Jain Acharya who lived in the 5th century CE. He is known for his scholarly contributions in the fields of logic, philosophy, and literature.

Based on the analysis, option 2, Khema, was not a Jain Acharya.