Answer:
The correct answer is option D: They set a dark and eerie mood appropriate for a serious play.
Step-by-step explanation:
The audience can guess that the first scene of Hamlet occurs in a castle late at night when the weather is cold. This combination of elements depicts a dark mood. Besides, the dialogue provides the readers with a gloomy feeling of strangeness and frighten due to the use of phrases such as "Tis now struck twelve; get thee to bed" and "tis bitter cold, And I am sick at heart." Both, the setting and the dialogue contribute to portray the appropriate mood for the serious play.