I KNOW THE ANSWER I LEARNED IT AS I WAS GROWING UP YOU KNOW MY FATHER SLAPPED ME AND THEN IT ALL CAME TO MY MIND, I KNEW THE ANSWER WAS PLASTIC WORMS! YOUR WELCOME (TRY THIS IT WORKS)
The answer should be C, Sudan red solution.
Sudan red solution dissolves in lipids, which can show a color of orange/red if lipid is present.
On the other hand, Biuret solution/reagent is used to test for proteins, and it'll show a color or purple if protein is present.
Iodine solution is used to test for the presence of starch, and it'll show a blue black color if starch is present.
And lastly, Benedict's solution is used to test for reducing sugars, and it'll show a brick red color (or green as small amounts) if reducing sugars are present after heating under boiling water bath.
The advantage of a phototropism is that the plants grows in the direction of the sunlight and not into a shadowed direction where it would get less light