在详细地研究这个问题后，我们终于找到了解决它的方法。() A: Afterstudieditcarefully,wefinallyfoundoutasolutiontotheproblem. B: Studyingitcarefully,wefinallyfoundoutasolutiontotheproblem. C: Havebeenstudieditcarefully,wefinallyfoundoutasolutiontotheproblem. D: Havingstudieditcarefully,wefinallyfoundoutasolutiontotheproblem.