Answer:
Answer to D is yes it is possible as only two outcomes being correct or being incorrect, and this creates 1/2 being 50% chance.
Answer to E is yes it is unlikely, as when something is of equal chance this means each random answer has a likelihood of alternating.
After all making tea can include length of time factors to stir the milk, dissolve the sugar and nothing is specified if these factors were equally timed or not.
Furthermore the lady determining whether tea was added first with milk or not may have her taste sensory changed as one may be change of flavor to another equally also, considering tea strengths and any difference of batch leaves.
Explanation: