Which of the following is generally recognised as the fastest moving land snake in the world?

Introduction:
Speed is an important attribute for some snakes that hunt active prey or need to escape threats quickly. Among land snakes, one species is especially famous in general knowledge and wildlife literature for its high ground speed. This question asks you to identify that snake from four well known venomous species.

Given Data / Assumptions:
- Options are black mamba, king cobra, Russell's viper and Indian cobra. - The focus is on land speed, not swimming or striking speed. - We consider typical maximum speeds recorded in the wild. - All listed snakes are venomous, but their speeds differ.

Concept / Approach:
The black mamba of Africa is widely recognised as one of the fastest, if not the fastest, land snakes. Reports suggest that it can move at speeds around 15 to 20 kilometres per hour over short distances. King cobras, Russell's vipers and Indian cobras can move quickly but are not usually credited with the same top land speed in common references. Therefore, recalling this fact points directly to black mamba as the correct answer.

Step-by-Step Solution:
Step 1: Recall reading or hearing that the black mamba is a very fast and agile snake. Step 2: Recognise that it inhabits open savannas where speed is useful for hunting and escaping. Step 3: Compare this with the behaviour of king cobras, Russell's vipers and Indian cobras, which are dangerous but not usually described as the world's fastest snakes. Step 4: Select black mamba as the snake that best matches the description of fastest moving land snake.

Verification / Alternative check:
Many wildlife documentaries, articles and exam oriented GK notes explicitly say that the black mamba is the fastest moving land snake. Some lists may also mention sidewinders or other species, but black mamba consistently appears as a top answer, especially in older and widely used sources. This confirms that black mamba is the expected choice for this question.

Why Other Options Are Wrong:
King cobra: The longest venomous snake and quite fast, but usually highlighted for its size and venom, not for holding the speed record. Russell's viper: Very dangerous and responsible for many bites, yet it is not especially noted for extreme speed. Indian cobra: Iconic in South Asia, with characteristic hood, but again the main focus is venom and cultural presence, not maximum running speed.

Common Pitfalls:
Because all the listed snakes are well known and feared, some learners may guess based on familiarity instead of recalling which one is associated with speed. Another confusion arises from different sources mentioning sidewinder desert snakes. For the specific combination of options in this question and for most exam level general knowledge, black mamba remains the most appropriate answer.

Final Answer:
The fastest moving land snake in the world among the options given is the Black mamba.