The answer is C. Overpopulation. Because life expectancy has increased, the number of people that are alive on Earth at one time has also increased. In many regions of the world, more babies are being born than the number of people dying, causing the populations to grow, and as populations increase, the risk of overpopulation becomes feasible.
A circuit with many paths for the current to travel through and not simply one is classified as a parallel circuit. Here the circuit can have many loops of resistors or light bulbs that can be attached.
Electron affinity increases upward for the groups and from left to right across periods of a periodic table because the electrons added to energy levels become closer to the nucleus, thus a stronger attraction between the nucleus and its electrons.
