Climate changes involve factors, both internal and external. External ones include
A. Feedback between the atmosphere, occean and land surface
B. Solar variability
C. Earth's orbit alteration
D. Variability within the climate system
E. Volcanic activity
Choose the correct answer from the options given below:
1
A, B and C only
2
B, C and E only
3
C, D and E only
4
A, B and E only