The correct answer is that "t<span>roponin holds the tropomyosin in place on the actin".
In excitation-contraction coupling, tropomyosin prevents the interaction between actin and myosin in resting muscles. In the event of excitation, there is release of calcium from the sarcoplasmic reticulum wherein the troponin will bind this calcium and will release tropomyosin and expose myosin enabling it to attach to actin and therefore facilitating muscle contraction.</span>
Answer: Image D has the most direct sunlight
Explanation:
Since direct sunlight is supposed to be intense, it can't be B or C. Sunlight is most intense in summe, so winter and fall are out. Now we have A and D left. The sun is illustrated in image D and the area the sun covers is larger than image A's, so image D has the most direct sunlight.