Molecular biologists are interested in things like the level of gene expression (how much protein or RNA is present at any given time), which molecules are directly touching each other inside the cell, etc. ... Cell biology techniques, on the other hand, want to know what's going on inside intact cells.
( Try to see which one sounds best after reading this)
The answer is d because of heat and pressure
When 2 species bennift like fish cleaning a whale by eating off his skin