D. The stranger does not want his appearance revealed.
Step-by-step explanation:
In the paragraph, Mrs Hall is encountered with the stranger. The entire sequence of paragraph describes the appearance, body language and personality of the stranger to the reader.
The description of the stranger clearly depicts that the stranger does not want his appearance to be revealed to Mrs Hall or Teddy. He is not ready to show his face to anyone.
The author describes stranger in a typical way, such as: shown to wear a fez, dark glasses and a purple dressing gown. Though Mrs Hall lights up fire in the house for heat to be produced in that cold weather, the stranger continues to wear his coat and doesn't remove his glasses too.