Correct option is B
The modern architecture movement is often associated with the early 20th century, and the year 1920 marks a significant period when many of the principles of modern architecture began to coalesce. This was a time when architects were starting to develop and promote ideas that would later become central to modernism, such as functionalism, minimalism, and the use of new materials and technologies. While the 1932 exhibition at MoMA is a key milestone, the roots of modern architecture can indeed be traced back to the 1920s.
Therefore, the correct answer is (b) 1920.
