Light is

a. electric and magnetic fields that oscillate perpendicularly to each other.
b. electric and magnetic fields that oscillate in a random direction relative to each other.
c. an oscillating electric field alone. an oscillating magnetic field alone.
d. electric and magnetic fields that oscillate parallel to each other.

a. electric and magnetic fields that oscillate perpendicularly to each other.

Explanation:

Light travels in the form of electromagnetic wave which contains electric and magnetic field , these two fields lie perpendicular to each other and both of them lie perpendicular to direction of propagation of wave. The electric and magnetic fields oscillate in magnitude or change sinusoidally in magnitude.

d. air pressure decreases as altitude increases.

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.