Which hex sequence identifies a PNG file signature?

• A. 89 50 4E 47 0D 0A 1A 0A
• B. FF D8 FF E0
• C. 25 50 44 46
• D. 50 4B 03 04 14 00 06 00

Answer: (A)

Recognizing file signatures (magic numbers) from the first bytes is how you identify a file’s format. A PNG file’s header starts with exactly eight bytes: 89 50 4E 47 0D 0A 1A 0A. The initial 89 helps flag binary data, the next four bytes 50 4E 47 spell “PNG” in ASCII, and the last four bytes 0D 0A 1A 0A are control characters that complete the header. Because the given sequence matches this eight-byte signature precisely, it identifies a PNG file.

The other sequences correspond to different formats: FF D8 FF E0 is the start of a JPEG image, 25 50 44 46 represents “%PDF” for a PDF document, and 50 4B 03 04 14 00 06 00 is the PK header used by ZIP archives.