Q:

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

• 1
  Only (I) is correct
• 2
  Only (II) is correct
• 3
  Only (III) is correct
• 4
  Both (I) and (II) are correct
• 5
  No correction required