Sometimes a text in picture format is shown on certain web page and you are asked to enter the same text in a text box. Such text shown in picture format is known as

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Accepted Answer

The correct option is (2):
A **CAPTCHA** is the precise security mechanism described in the question. The acronym stands for **Completely Automated Public Turing test to tell Computers and Humans Apart**. Its core purpose is to protect websites and online services from automated abuse, such as spam generation, bulk registration, and denial-of-service attacks, by presenting a challenge that is simple for a human to solve but extremely difficult for a machine. The most common form, which matches the scenario, involves distorted, blurred, or obscured text embedded within an image, requiring the human user to interpret and accurately re-enter the characters into a designated text box. This anti-automation test is essential for maintaining the security and integrity of online systems.

The incorrect option is (1):
The term O. T. P. stands for **One-Time Password**. An OTP is a security code, typically a short string of numbers, that is automatically generated and valid for only a single login attempt or transaction. It is used as a form of multi-factor authentication to verify the user's identity and is usually sent to the user via SMS, email, or an authenticator application. This is an authentication token, not an image-based challenge designed to test if the user is a human.

The incorrect option is (3):
A Q. R. Code is an abbreviation for **Quick Response Code**, which is a type of two-dimensional barcode. This code is designed to be read by a camera or scanner to quickly store and retrieve information, such as a website URL, contact details, or payment information. It is a compact data storage and communication tool used for convenience, not a challenge-response mechanism for differentiating humans from automated software.

The incorrect option is (4):
A **Link**, or Hyperlink, is a fundamental element of the web used for navigation. It is a reference to data that a user can follow by clicking or tapping, which then directs the web browser to another document or resource. While a link can be an image itself, its function remains purely navigational. It is entirely unrelated to presenting a distorted text challenge in a picture format that a user must manually transcribe to prove their humanity.