When fixer solution enters the developing tank, it will cause?

The correct response to the question is that when fixer solution enters the developing tank, it causes fogged films. This occurs because the fixer, which is used to remove unexposed silver halide from the film, should only be applied after the film has been properly developed. If fixer enters the developing solution prematurely, it interferes with the developing process and prevents the image from forming correctly.

This premature exposure to fixer leads to a loss of contrast and detail in the image, resulting in a foggy appearance on the film. The halide crystals that are not meant to be eliminated during the developing phase remain on the film, causing an overall cloudy effect. Therefore, it is essential that each chemical is used in the correct order and that contamination between the developing and fixing stages is avoided to ensure the integrity of the developed film.