What is a jet stream?

Jet streams are relatively narrow bands of strong wind in the upper levels of the atmosphere. The words blow from west to east in jet streams but the flow often shifts to north and south. Jet streams follow the boundaries between hot and cold air. The earth's rotation is responsible for the jet stream as well.

this protocol provides a detailed procedure for total protein extraction for western blot analysis from achieved samples following trizol isolation of rna.

i think that d. wind is the answer.   i missed the question when i answered a. currents.