Option 1 states that Himalayan rivers have water throughout the year. This means that these rivers do not dry up at any point during the year.

Option 2, the correct answer, states that these rivers receive water only from rains. This implies that the water in these rivers solely comes from rainfall and not from any other sources.

Option 3 claims that Himalayan rivers receive water from both rains and melted snow. This suggests that the rivers are fed by both rainfall and the melting of snow in the mountains.

Option 4 states that most of the Himalayan rivers are perennial, meaning that they flow continuously throughout the year.

In summary, option 1 and option 4 are true about the Himalayan rivers, while option 2 is false.