Concept:The NCNC's 1947 London delegation was sent to protest against the unpopular Richards Constitution.Explanation:The delegation pressed the British government to revise the Richards Constitution.They argued that the constitution was imposed without adequate consultation with Nigerians.Although they also raised other concerns, their central demand was constitutional revision, not immediate independence or free education.Therefore, the action of the delegation matches the call for a revision of the Richards Constitution.Answer:C. a revision of the Richards Constitution.