Answer: Option B.
Explanation:
The first experiment of the passage shows that treatment with TGFBR1 and TGFBR2 antagonists led to lower levels of epithelial cell production. For this conclusion to be strongly valid, we want to show a positive correlation between TGFBR activity and epithelial proliferation.
Well he looked at the contents and saw they some of them had similar shapes so
ATP<span> is responsible for cocking (pulling back) the myosin head, ready for another cycle. When it binds to the myosin head, it causes the cross bridge between actin and myosin to detach. </span>ATP<span> then provides the energy to pull the myosin back.</span>
