What idea do the words little and serene suggest in this text

Hello. This question is incomplete. The complete question is:

With infinite complacency men went to and fro over this globe about their little affairs, serene in their assurance of their empire over matter.

What idea do the words little and serene suggest in this text?

The idea that humans crave challenges and activity

The idea that human size was insignificant to that of Martians

The idea that humans were insignificant and oblivious

The idea that humans were obsessed with small things

Answer:

The idea that humans were insignificant and oblivious

Explanation:

The words "little" and "serene" convey a sense of inferiority and lack of importance. They were used in the text to show that men and the actions provoked and carried out by them are unimportant, without depth. These men and their actions were insignificant and oblivious, they were so small that they did not cause any relevant circumstances and for that reason the men presented a serenity, since they knew that they were not provoking anything.