The formula for frequency is f = 1/T where f is frequency and T is period in seconds.
You have you period which is 0.008s and that is all you will need to solve or frequency in a wave:
f = 1/2
f = 1/0.008s
f = 125Hz

Actually Welcome to the Concept of the Optical Devices.
Now basically here the devices that can spread light over apart are the CONCAVE LENS and Convex mirror.
so the Answer is
C. B and D
Because Florida is wet and humid, while California is dry and non-humid. Florida also contains lots of lakes which evaporate to create thunderstorms.
do not obey ohm's law so it's a I believe