Which detail in the passage changes the mood from unease to horror?
o intense darkness
o
"a gasp
an irrepressible tremor
o "certain low and indefinite sounds

D. "certain low and indefinite sounds"

Explanation:

In the passage, the detail that changes the mood  from unease to horror is the  "certain low and indefinite sounds".

When the low and indefinite sounds are heard the mood of even the readers actually change to horror. Those type of low and indefinite sounds are actually what makes movies, poems or stories have the horror genre and become suspense-filled.

Though this question didn't carry enough information about the passage. I answered this with the best of my knowledge.

the answer is luis.

  someone can be considered a dynamic person by being energitic and forceful, but other aspects of being dynamic is having a lot of ideas and enthusiasm. luis his little brother with his homework, and later he teaches his younger brother how to ride a bike without training wheels, which takes a lot of patience, dedication and involvement.