Which heterocyclic compound does NOT contain nitrogen

The same question, asked 2 times: 14 May 2024 S1*, 25 Apr 2025 S2. Every wording below, oldest first.

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Question 1
14 May 2024 S1
72 $Which from following molecules does NOT contain nitrogen in it?$
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Question 2
25 Apr 2025 S2
60 $Which from following compounds does NOT contain nitrogen in it?$
Tap an option to check your answer.