'Visionary' means a person with original ideas about what the future will be like or thinking about the future with wisdom. E.g. He is a visionary keen on policy-making. Thus, option A is correct as visionary means dreamer. 'Savant' means a learned person. 'Philosopher' means a person engaged in philosophy. 'Saint' means a virtuous or kind person. Hence, options B, C and D are incorrect.