Which of the following are the most important reason/reasons of flood becoming a destructive natural hazard in the Ganga-Brahmaputra valley ?
1. Due to population pressure more and more people are living in flood prone areas 2. Increased frequency and magnitude of landslide and soil erosion in the upper catchments 3. Increase in the amount and intensity of rainfall in the north-western part of India
Select the correct answer using the code given below:

Options

A. 1 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2 and 3