Consider the following countries: I. Austria II. Bulgaria III. Croatia IV. Serbia V. Sweden VI. North Macedonia. How many of the above are members of the North Atlantic Treaty Organization?

• I. Austria — Not a NATO member; it is militarily neutral. Verdict: Incorrect.
• II. Bulgaria — NATO member since 2004. Verdict: Correct.
• III. Croatia — NATO member since 2009. Verdict: Correct.
• IV. Serbia — Not a NATO member; it maintains military neutrality. Verdict: Incorrect.
• V. Sweden — NATO member since 2024. Verdict: Correct.
• VI. North Macedonia — NATO member since 2020. Verdict: Correct.

So, 4 countries are NATO members: Bulgaria, Croatia, Sweden, and North Macedonia. Hence, (b) Only four.