CALAMITY'.In the given sentence, the use of the preposition 'of' is incorrect.The preposition 'of' is USED for expressing the relationship between a part and a whole.The determiner 'a' should be used in PLACE of the preposition 'of'.The determiner 'a' is used to modify non-specific or non-particular nouns (here, natural calamity). Hence, the correct answer is OPTION 4.Correct Sentence: Instead of panicking, it is good to keep yourself safe and not get anxious whenever there is a natural calamity.'Keep' does take a reflexive pronoun in CERTAIN cases. It is grammatically correct, but less common.