Read the following context and choose the best option to answer the question.
Context: " One day in the summer of 1971 , my parents held hands , closed their eyes and jumped out of their conventional marriage into something strange and new . I was 9 years old at the time , and we were camping at Betsy Lake in the High Uintas Wilderness with another family of five . We were halfway into the camping trip when the six of us kids realized our parents had mixed and matched : My father was in the tent with their mother , and their father was in the tent with my mother .
Question: Why would the children be unnerved on the camping trip ?
Options: 
A. Betsy Lake was a dangerous place .
B. Their parents hated one another .
C. Their parents went missing .
D. Their parents were swapping each other .


D