**Core Concept**
DNA footprinting is a laboratory technique used to identify specific DNA-protein interactions. This method involves the protection of DNA sequences from chemical cleavage by bound proteins, allowing researchers to map the location and specificity of protein-DNA interactions.

**Why the Correct Answer is Right**
The correct answer involves the use of dimethyl sulfate (DMS), a chemical reagent that methylates guanine residues in DNA. When DMS-treated DNA is then cleaved with piperidine, the resulting fragments reveal protected regions where proteins are bound. This is because the protein-protein-DNA complex shields guanine residues from methylation by DMS, resulting in a characteristic footprint of protected DNA sequences. The resulting DNA fragments can be analyzed using gel electrophoresis to identify specific binding sites.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not a correct description of DNA footprinting, as it does not involve the use of a chemical reagent to modify DNA.
**Option B:** This option is incorrect, as DNA sequencing is a technique used to determine the nucleotide sequence of a DNA molecule, not to detect protein-DNA interactions.
**Option C:** This option is incorrect, as restriction enzyme digestion is a technique used to cut DNA at specific recognition sites, but it does not involve the protection of DNA sequences by bound proteins.

**Clinical Pearl / High-Yield Fact**
DNA footprinting is a powerful tool for understanding the molecular mechanisms of gene regulation and has been instrumental in identifying transcription factor binding sites, which are critical for gene expression.

**Correct Answer: C. Restriction enzyme digestion is used to detect DNA footprints.