Which of the following statements is true?

A hypothesis always leads to a theory which leads to a law.

A hypothesis always leads to a law which leads to a theory.

A hypothesis must lead to a theory only.

A hypothesis can lead to either a theory or a law. <<<<<<<<<

correct.

To determine which statement is true, let's break down the concepts of hypotheses, theories, and laws in the scientific context.

In the scientific method, a hypothesis is a proposed explanation for a phenomenon or a set of observations. It is an educated guess that can be tested through experimentation or further investigation. A hypothesis is a starting point for scientific inquiry, but it doesn't automatically result in a theory or a law.

A scientific theory is a well-substantiated explanation of some aspect of the natural world. It is based on a collection of evidence and has been repeatedly tested and confirmed through various experiments and observations. A theory goes beyond a single hypothesis and offers a comprehensive framework to understand a specific phenomenon. It is often widely accepted in the scientific community.

A scientific law is a description of an observed phenomenon or a pattern in nature. It is a concise statement that summarizes a regularity or relationship between variables. Unlike a theory, a law doesn't explain the underlying mechanism or provide a comprehensive understanding; instead, it describes what will happen under specific conditions.

Diving into the statements:

Statement 1: "A hypothesis always leads to a theory which leads to a law."
This statement is not accurate. While a hypothesis can contribute to forming a theory, it doesn't always lead to a theory, and a theory doesn't always lead to a law. The relationship between these three concepts is not a strict linear progression.

Statement 2: "A hypothesis always leads to a law which leads to a theory."
This statement is also not accurate. As mentioned earlier, a hypothesis doesn't always lead to a law, and the relationship between a law and a theory is not sequential.

Statement 3: "A hypothesis must lead to a theory only."
This statement is not accurate either. While a hypothesis can contribute to the development of a theory, it is not the only path to theory formation.

Statement 4: "A hypothesis can lead to either a theory or a law."
This statement is true. When a hypothesis is extensively tested, and sufficient evidence is gathered, it can lead to the formulation of a theory. Alternatively, if a hypothesis describes a fundamental and universally applicable relationship, it can be elevated to the status of a law. Both outcomes are possible, depending on the research findings and scientific consensus.

Therefore, the correct answer to the question is the fourth statement: "A hypothesis can lead to either a theory or a law."