Explanation:

- Facta probanda refers to the material facts that must be proven in a legal case. These are the essential facts necessary to establish the claim or defense.

- Facta probantia are the evidential facts. These are details that serve as evidence to prove the facta probanda.

- In legal pleadings, only the facta probanda need to be stated. They represent the core issues requiring proof.

- Facta probantia, as evidence, are generally introduced during the actual trial or hearing.

Option 2, facta probanda, must be stated in pleadings.