GMAT Sentence Correction (SC) | The data being collected in the current geological survey

A. The data being collected in the current geological survey are providing a strong warning for engineers as they consider the new dam project, but their greatest importance
First of all, data are plural. A has no problem. being is correctly used. The subject is data.

B. The data being collected in the current geological survey provide a strong warning for engineers as they consider the new dam project, butits greatest importance

C. The data collected in the current geological survey is providing
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