Given here are four sentences. The first sentence is in correct order while the rest of the sentences are jumbled. Pick the option that gives their correct order.
A. Basking in the sun for some time regularly is recommended for improving one’s physical condition.
B. One should, however, exercise caution while exposing oneself to the sun.
C. To be more specific, it builds up resistance to infections and tones up the whole system.
D. This is because too much exposure to the sun may prove harmful to health.