Question

1. A committee of the Philippines House of Representatives has initiated a legislative inquiry on a controversial issue affecting public interest. During the inquiry, several witnesses were summoned and testimonies were given. However, one of the witnesses invoked the right against self-incrimination and refused to answer certain questions posed by the legislators, citing that his answers may lead to criminal charges against him.

Discuss whether the witness can validly invoke the right against self-incrimination during a legislative inquiry. Cite the constitutional provision that supports your answer alongside any relevant jurisprudence.

2. The Senate of the Philippines decided to conduct an oversight function on the implementation of a newly enacted law concerning environmental protection. During the oversight hearings, it was revealed that some government agencies failed to effectively enforce the provisions of the law, resulting in significant damage to the environment.

Explain the nature and purpose of oversight functions of the legislative branch. Discuss whether the Senate has the authority to compel the concerned government agencies to take corrective actions based on the findings of the oversight function. Cite relevant provisions from the 1987 Constitution and any applicable laws or legal principles to support your answer.