In humans, methylation of chromosomal dna is a signal that often leads to

-an increase in the rate of gene transcription

-dna replication

-homologous recombination

-formation of heterochromatin

-insertional mutagenesis

The correct answer will be option-formation of heterochromatin

Explanation:

Methylation of DNA is the epigenetic mechanism which controls the expression of a gene by adding a methyl group to the cytosine bases in eukaryotic DNA.

The methylation of DNA converts the cytosine residues to the  5-methylcytosine catalysed by DNA methyltransferase enzyme. This results in the silencing of the gene and transcription get switched off.

Studies have shown that DNA methylation is involved in the formation and maintenance of the heterochromatin structure which is the condensed form of the chromatin in which transcription is switched off.

Thus, the formation of heterochromatin is the correct answer.

it creates acid rain