In prophase of mitosis, the genes → chromatin (DNA + protein) are uncoiled, so they are visible. This makes the chromatin into chromosomes, thin, spindle-like things. These are what we usually correlate with genes and can see. This supports option D, which is your answer.
Blood clots form when platelets and plasma proteins thicken to form a sort of solid mass. They can form from an injury, blood flowing slowly through your system, or even for no obvious reason.
