The correct answer is option 1, which states that there are two parallel mountain ranges in the longitudinal extent of the Himalayas. The Himalayas are known for their peaks and rugged terrain, and they stretch over a vast area across several countries in South Asia. In terms of their longitudinal extent, the Himalayas can be divided into two main parallel ranges: the Greater Himalayas and the Lesser Himalayas. The Greater Himalayas, also known as the Higher Himalayas or the Inner Himalayas, are the northernmost and highest range, containing some of the world`s tallest peaks, including Mount Everest. The Lesser Himalayas, also called the Middle Himalayas or the Outer Himalayas, are located south of the Greater Himalayas and are lower in altitude. So, with these two parallel ranges, the correct answer is indeed two.