Correct option is B
Option (b) is the correct order of the given sentences.
Explanation:
· Sentence 1 introduces the feature of the 21st century.
· Q: Begins with "the improvement of the income and…"—a logical continuation.
· R: Adds “living conditions of the…”—completing the object of improvement.
· S: Adds the result “leading to…”—what this improvement has led to.
· P: “greater security and education which…” gives a defining clause leading into 6.
· Sentence 6 completes the meaning “has meant greater political power.”
· This sequence makes a grammatically and contextually coherent sentence.