GMAT Sentence Correction (SC) | Re: Concerns about public health led to

The sentence talks about a specific time in the past , further the action was completed in the past time frame and hence only Simple past tense should be used -

Simple Past-



Hence answer must be (A)

Please visit the following link for clearing the concepts ( if required ) of Verb Tenses in English -

http://www.englishpage.com/verbpage/simplepast.html