Which of the following is/are factors that cause variation in amount of insolation on earth?
(A) the rotation of the earth on its axis.
(B) the angle of inclination of the Sun's rays.
(C) the length of the day.
Choose the correct option.
1
Only (A) is true
2
Only (A) and (B) are true
3
Only (A) and (C) are true
4
(A), (B) and (C) all are true