**Core Concept:**
In the context of law, an oath is a solemn affirmation to tell the truth in a court of law. False evidence, or perjury, committed after taking an oath is a serious offense. The Indian Evidence Act (IEA) governs the admissibility and production of evidence in Indian courts.

**Why the Correct Answer is Right:**
The correct answer, **A. Indian Evidence Act (IEA)**, outlines the principles related to the admissibility of evidence and the penalties for perjury, including false evidence given after taking an oath. This act ensures the fairness and integrity of judicial proceedings by determining the types of evidence that can be considered and the consequences for defying the court's oath.

**Why Each Wrong Option is Incorrect:**

**B. Indian Penal Code (IPC)**: The Indian Penal Code (IPC) is a broad criminal law statute that deals with offenses against persons and property, but it does not specifically address the penalties for perjury or false evidence.

**C. Indian Constitution:** The Indian Constitution is the fundamental document that establishes the framework of the Indian government, but it does not outline the penalties for perjury or false evidence.

**D. Common Law and Equity:** Common Law and Equity are legal principles derived from English law, but they are not specific to the Indian context and do not address perjury or false evidence.

**Clinical Pearl:**
The Indian Evidence Act plays a crucial role in determining the admissibility of evidence and the consequences of perjury, ensuring the fairness of judicial proceedings. It highlights the importance of understanding the relevant legal statutes when dealing with oaths and evidence in a court of law.

**Explanation:**
In the context of perjury and false evidence, the correct answer is the Indian Evidence Act (IEA) as it directly addresses the penalties for defying an oath and providing false evidence in a court of law. The other options, such as the Indian Penal Code, Indian Constitution, Common Law, and Equity, are broad legal principles that do not specifically address perjury or false evidence.

**Correct Answer: Indian Evidence Act (IEA)**