-Mi hijo estudió tanto para ese examen... -Pues ________ mucho pero no lo ha aprobado. My son studied so much for that exam... -Well he may have studied a lot but he didn't pass.estudiaría estudiaráha estudiadoestudiase

As the coditional and the simple future both seem to be able to serve the same purpose of objection or disbelief. would "estudiará" also be correct?  I know the question was asked in the context of a specific lesson but taken out of context such as in my notebook where I had both the use of simple future and conditinal lessons, without a hint, it can be difficult to choose.