In Indian geography, the term Doab refers to what kind of landform?

Introduction / Context:
Many Indian geographical terms come from Persian, Hindi or other regional languages and are frequently used in discussions of river systems and agriculture. One such term is Doab, often encountered in the context of the Indo Gangetic plains, for example the Ganga Yamuna Doab. Understanding the meaning of this word is essential for questions related to river basins, alluvial plains and irrigation. This question tests whether you know exactly what kind of landform a Doab represents in Indian geography.

Given Data / Assumptions:

• The term under discussion is Doab.
• The context is Indian geography and landforms.
• The options provide different possibilities: land between two mountains, between two lakes, between two rivers or between two seas.
• No numerical calculation is needed; the task is purely definitional.

Concept / Approach:
The word Doab is derived from two Persian words: Do meaning two and Ab meaning water or river. Therefore, Doab literally means the land between two rivers. In India, the most famous example is the fertile tract between the Ganga and Yamuna rivers, called the Ganga Yamuna Doab. The approach to solve this question is to recall this linguistic origin and the real world examples of Doabs in the Indo Gangetic plain. Once you correctly understand the etymology, it becomes easy to identify the correct option and eliminate the others.

Step-by-Step Solution:
Step 1: Break down the term Doab into its components: Do and Ab. Step 2: Recall that Do means two and Ab refers to water or river in Persian based terminology used historically in India. Step 3: Combine the meanings to obtain land between two rivers. Step 4: Compare this meaning with the options given in the question. Step 5: Select the option that states a land between two rivers, because it directly reflects the correct definition of Doab.

Verification / Alternative Check:
To verify, think of well known Doabs described in school textbooks: the Ganga Yamuna Doab between the Ganga and Yamuna rivers and other smaller Doabs formed by tributaries in the northern plains. These are always described as tracts of land bounded by two rivers. Historical administrative divisions during the Mughal and British periods also used the term Doab specifically for land between rivers. Since no standard usage of Doab refers to land between lakes, mountains or seas, this cross check confirms that the correct meaning is land between two rivers.

Why Other Options Are Wrong:
A land between two mountains is generally referred to as a valley or a pass, not a Doab. A land between two lakes does not have a widely used specific traditional term like Doab in Indian geography. A land between two seas would be better described as an isthmus, not a Doab. Therefore, these options do not match either the etymology or the established geographical usage of the term Doab and are incorrect for this question.

Common Pitfalls:
Some learners mistakenly associate the word Doab with general landforms and may loosely think of it as any area between two natural features, leading to confusion with mountains or seas. Others may forget the Persian origin and guess based on partial memory. To avoid these errors, always connect such terms with their language roots and classic examples. Regularly revising key Indian geographical vocabulary like Doab, Bhabar, Terai and Khadar helps strengthen your conceptual understanding and improves your accuracy on examination questions.

Final Answer:
In Indian geography, the term Doab refers to a land between two rivers, so that is the correct option.