Directions: Read the Assertion (A) and Reason (R) carefully and choose the correct alternative. Assertion (A): Most of the Himalayan rivers are perennial and flow throughout the year. Reason (R): These rivers are fed by melting snow and glaciers in the high Himalayan mountains.

Introduction / Context:
This Assertion and Reason item is based on Indian physical geography and river systems. It distinguishes Himalayan rivers from peninsular rivers and asks whether their perennial character is correctly explained by their source of water. Understanding why certain rivers flow throughout the year while others are seasonal is an important concept in geography, water resource planning, and environmental studies.

Given Data / Assumptions:

• Assertion (A) states that most of the Himalayan rivers are perennial.
• Reason (R) states that these rivers are fed by melting snow.
• Perennial rivers are rivers that have water flow in all seasons of the year.
• Himalayan rivers include major rivers like the Ganga, Yamuna, Indus, and Brahmaputra.

Concept / Approach:
Himalayan rivers originate in high mountain regions where there are glaciers and permanent snowfields. Throughout the year, especially during warmer months, snow and ice melt and supply water to these rivers. In addition, they receive rainfall from monsoon systems. Because they have both glacial melt and rainfall as sources, they tend to maintain flow year round. In contrast, many peninsular rivers depend mainly on monsoon rain and may become seasonal.

Step-by-Step Solution:
Step 1: The Ganga, Yamuna, Brahmaputra, and Indus all arise from glaciated regions in the Himalayas. Step 2: Even outside the main monsoon season, glaciers and permanent snowfields slowly melt and provide a steady base flow of water to these rivers. Step 3: During monsoon, heavy rainfall further increases their discharge, often causing floods, but the basic flow remains even in drier seasons due to snow melt. Step 4: Because of this continuous supply, most Himalayan rivers are described as perennial, meaning they flow throughout the year. Thus Assertion (A) is true. Step 5: Reason (R) accurately states that these rivers are fed by melting snow. This is one of the main reasons for their perennial nature. Therefore Reason (R) is also true. Step 6: The presence of glaciers and snow in upper catchments is the direct physical cause that explains why these rivers do not run dry during non monsoon months. Hence Reason (R) correctly explains Assertion (A).

Verification / Alternative check:
Standard school geography textbooks classify Indian rivers into Himalayan and peninsular systems. They explicitly state that Himalayan rivers are perennial because they are snow fed and rain fed, while many peninsular rivers are mainly rain fed and thus seasonal. This classification and explanation match exactly with the statements in the question, confirming both their truth and the logical connection between them.

Why Other Options Are Wrong:
Any option describing Assertion (A) as false contradicts this well accepted classification. Options that say Reason (R) is false ignore the clear role of glacial melt in river hydrology. The option stating that both are true but R does not explain A is also incorrect because snow melt is precisely the reason these rivers remain perennial.

Common Pitfalls:
Learners sometimes assume that monsoon rainfall alone is sufficient to make a river perennial, overlooking the importance of glaciers and snowfields. Others may confuse the behaviour of Himalayan rivers with that of shorter, non snow fed rivers in the peninsula. Keeping the distinction clear between different river systems helps avoid such errors.

Final Answer:
Both Assertion (A) and Reason (R) are true, and Reason (R) correctly explains Assertion (A), so the correct option is Both Assertion (A) and Reason (R) are true, and Reason (R) correctly explains Assertion (A).