The research project on climate change (6)___(undertake) by a team of scientists from various disciplines. Each researcher (7)___ (bring) their unique expertise to the project. Over the years, the team (8)___ (collect) an extensive dataset, which (9)___ (analyze) to understand the complex interactions between different climate variables.

Explanation: The verb is for the action (9) - (analyze). The sentence is: '...which (9) (analyze) to understand the complex interactions...' The subject 'which' refers to the 'extensive dataset' (singular, inanimate), and the action 'analyze' is an ongoing state or general fact related to the existing dataset. The verb should be in the **Passive Voice** because the dataset is being acted upon (analyzed). A plausible tense is the **Simple Present Passive**: **is analyzed**.