Answer:
A) December
B) March and September
C) June
Step-by-step explanation:
Earth is slightly tilted on its axis and that is the reason some regions have more or less sunlight at different times in a year. If earth was not positioned slightly tiled it would have stationed itself at a static position right above the equator. Which means there would be no season and sunlight falling on certain region of earth would be fixed. Hence, the concept of equinoxes and solstices would have never come into being.
There are two solstices, winter solstice and summer solstice. Winter solstice happens in December 21st or 22nd and marks the beginning of winters. However summer solstice happens on June 20th or 21st and marks the beginning of summers. The days are shortest during winter solstices and longest during summer solstices. On the other hand Equinoxes occur around March 21st and September 23rd. at this time of year day and nights are of equal length as sun is right above the equator.