Question

how do forensic analysts reveal fingerprints on rough surfaces like paper or cloth?
by applying chemicals that react with acids and salts
by using led light
by dusting powder
by photographing directly

Explanation:

Fingerprints on rough surfaces (paper/cloth) contain acids/salts from sweat. Chemicals (e.g., ninhydrin for paper) react with these to form visible marks. Dusting works on smooth surfaces; LED light and direct photography are ineffective here.

Answer:

A. By applying chemicals that react with acids and salts