Concept:After the word all, use the relative pronoun that, not what.Explanation:The sentence is: All ______ the president said was reported in the dailies.The word all cannot be followed by what, so expressions like all what are incorrect.Instead, we use all that or simply what alone.Here, that acts as a relative pronoun connecting the clause to all.Therefore, the correct completion is All that the president said was reported in the dailies.Answer:C. that