Each cell expresses, or turns on, only a fraction of its genes. the rest of the genes are repressed, or turned off. the process of turning genes on and off is known as gene regulation. gene regulation can occur at any point during gene expression, but most commonly occurs at the level of when the information in a gene's dna is transferred to mrna. a) post-translation b) replication c) transcription d) translation

The answer would be:

C. Transcription

Here's a little more about gene regulation:

Gene regulation as mentioned already, is the process of turning genes on and off. In multicellular organisms, the different cells have the same DNA in them but through gene regulation, different sets of genes are expressed. The genes that are expressed determine the function and appearance of the cell.

oxygen +1 most likely

when the displaced particles are perpendicular to the direction the wave travels, is called a transverse wave, whereas in longitudinal wave the displace practices are parallel to the direction of the wave.

in the given image:

first image shows - longitudinal wave

second image shows - transverse wave

third image shows - longitudinal wave

fourth image shows - longitudinal wave