The "Hermit Kingdom" is increasingly isolating "itself because of its" nuclear ambition that threatens its neighbourhood and the world at large.
(I) isolated because of
(II) isolating themselves because of
(III) isolated themselves because of their

Options

A. Only (I) is correct
B. Only (II) is correct
C. Only (III) is correct
D. No correction required

Answer

D

Explanation

The given sentence is grammatically correct as the sentence is not in Passive form. It is clearly follows the syntax of Present Continuous Tense and the use of reflexive pronoun "itself" is correct as it is used for the subject "The Hermit Kingdom". Moreover, the three phrases given in options do not follow the correct structure required for the sentence to make it grammatically correct. Hence, (d) is the correct option.