When your blood pressure is low, choose a choice below that explains what occurs. A. The nervous system signals smooth muscles in the blood vessels to relax to decrease blood pressure.
B. The nervous signals smooth muscles in the blood vessels to relax to increase blood pressure.
C. The nervous system signals smooth muscles to contract to decrease blood pressure.
D. The nervous system signals smooth muscles in the blood vessels to contract to increase blood pressure

The correct option is;

D. The nervous system signals smooth muscles in the blood vessels to contract to increase blood pressure

Explanation:

The contraction or relaxation of the vascular smooth muscles lead to the blood vessel volume change and blood pressure change such that the blood is redirected to regions of the body that requires instantaneous increased oxygen intake. As such the nervous system signals the blood vessel's vascular smooth muscle to contract, through vasoconstriction so as to raise the blood pressure, when the blood pressure is low.

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.