In PHP, what is the name of the main configuration file that controls settings such as error reporting, extensions, and upload limits?

Introduction / Context:
PHP is a widely used server side scripting language, and its behavior is controlled by a central configuration file. This file sets up options such as error reporting levels, file upload limits, default time zone, and extensions to load. Knowing the correct name of this file is important for system administrators and developers who need to tune the environment. This question asks for the standard name of the main PHP configuration file.

Given Data / Assumptions:

• We are using a typical PHP installation on a web server such as Apache or Nginx.
• PHP reads configuration from a central file at startup.
• The file name is the same across many platforms, although location may differ.
• The question is about the engine configuration file, not application level files.

Concept / Approach:
The standard name of the PHP configuration file is php.ini. The file extension ini reflects the traditional Windows style initialization files, but the format is also used on Unix like systems. Inside php.ini, you find directives such as display_errors, memory_limit, max_execution_time, and extension loading settings. Other file names in the options list either refer to generic configuration concepts or to application specific files, but they are not the default PHP engine configuration file.

Step-by-Step Solution:
Step 1: Recall that PHP documentation and hosting control panels refer to settings in php.ini when describing how to configure error reporting and extensions. Step 2: Compare the options. Option c, php.ini, matches the well known name exactly. Step 3: Option a, php.conf, might look plausible but is not the standard file name. Step 4: Option b and option d use similar patterns but are not recognized by the PHP engine as the main configuration file by default. Step 5: Option e, config.php, is often used by specific applications as their own configuration script, but it is not the global PHP configuration file.

Verification / Alternative check:
Running the phpinfo function on a server shows the path to the loaded configuration file, and it typically points to a file named php.ini. Server administration guides consistently instruct you to edit php.ini to adjust memory and upload limits or to enable extensions like PDO. This confirms that php.ini is the answer the exam expects.

Why Other Options Are Wrong:
Option a, php.conf, may exist in some custom setups or web server configurations but is not the default PHP configuration file. Option b and option d are simply made up names. Option e, config.php, is used by many frameworks and content management systems for their own application settings but does not control the PHP interpreter itself.

Common Pitfalls:
A common source of confusion is mixing up web server configuration files with PHP configuration files. For example, Apache might use httpd.conf, while PHP uses php.ini. Developers may also edit the wrong ini file if multiple PHP versions are installed on the same server. Using phpinfo to confirm which php.ini is active helps avoid such mistakes.

Final Answer:
The main PHP configuration file is named php.ini, which is option c.