Answer: use solar energy then
Explanation:
B. Mutations cause a person's body cells to divide uncontrollably. There isn't a signal for cells to stop dividing, so this can cause cancer because cancer cells won't stop dividing without this signal.
The right answer is C. I think, a. and d. are obviously not serious. B is not true, because Ag and Au are in the same group in the periodic table and therefore have the same number of electrons in the last level. So, they form ions with the same charge. C is true beacause Ag and Au have different numbers in the periodic table and different amount of protons and neutrons in their nucleuses.
It would be completely false to state that adult <span>brains have about five times the number of connections that a three-year-old has. The correct option among the two options that are given in the question is the second option. A child brain has twice as many connections than that of an adult brain. </span>