Answer:
The answer is explained below.
Step-by-step explanation:
Nadine Gordimer was a South African writer who was born in 1923 and died in 2014. She was given the Nobel Prize in 1991; she was also an activist and this can also be seen in her writing since her topics deal with racial issues, paying special attention to the Apartheid in her country; due to this regime, some of her books were banned.
A metaphor is a rhetorical device that is also a type of comparison using two things that are unrelated but for what the speaker says; this comparison is implied or implicit or hidden. In the text she also uses other types of comparison, such as simile, which is an explicit comparison between two things. The topic is the main idea in a work; in this case, fear is the topic of Gordimer's story. She uses a cage as a metaphor to compare it with security, since the family wants to have a higher wall, meaning that their security depended on it.