What is the lesson of the story "Who Can Replace a Man?"

A society will not be able to sustain itself and thrive. In Who Can Replace a Man Brian Aldiss describes a futuristic world in which machines are capable of thinking based on the tasks they have been designed to perform

even though there may be variations in human emotions over time, the poem “ a contribution to statistics” by wislawa symborska suggests that the only unchangeable characteristic is mortality.

the author poses a distinction between the approximate and non-approximate numbers which correspond to our need for certainty in life and the difficulty of achieving it. our efforts to measure the exact often fail because the world is not always clearly structured .the poem seems to imply   that the only thing that is certain and has an exact number is death.  

d.) gold is the correct answer