In theology, one gives an opinion on matters on which definite knowledge has so far been uncertain. 'Speculations' are opinions that are given by people on topics on which there is no certain knowledge while 'reflections' are opinions on events that occurred in the past. So 'speculations' is the correct choice here. Unattainable means something that has not been reached at all. Definite knowledge is attained in stages and not in one-go. So, 'unascertainable' that means 'not determinable with full certainty' i.e. knowledge which has been partly determined but not wholly is the right word to be used in this context. 'Proclamation' means an official/government edict while 'revelation' means uncovering of a divine or a spiritual secret. Revelation is the correct word in the theological context.
So, the answer is BAB.