Media kits are used in:

The correct option is:
A package of information, assembled by a company, to provide basic information about itself to reporters.

What is a Media Kit?
A media kit, also known as a press kit, is a pre-packaged set of promotional materials and informational resources compiled by a company or organization. The primary objective of a media kit is to provide journalists, reporters, and media outlets with all the essential, accurate, and up-to-date facts they need to write articles or report stories about the company.

Why Do Companies Use Media Kits?
When a company launches a new product, announces a major corporate event, or simply wants to increase brand awareness, it reaches out to the press. Journalists work under tight deadlines and may not have the time to research every detail about a company. By providing a structured media kit, the company makes it easy for reporters to access key information, such as:
- A company overview and history
- Executive biographies and headshots
- High-resolution logos and product images
- Press releases and contact details for PR representatives

Evaluating the Other Options:
- Package of media files: This definition is too generic. A simple folder of videos or images is not a media kit unless it is curated specifically to inform the press about a company.
- Information made digitally by the income tax department: The income tax department is a government regulatory body concerned with taxation and financial auditing, not public relations or journalism.
- A digitally kept folder which includes all kinds of media files of a particular field: This refers to a general industry archive or digital repository, whereas a media kit is specifically assembled by an individual company to represent itself to reporters.