Lanthanoid with a completely filled 4f orbital in the expected configuration (ytterbium)

The same question, asked 2 times: 16 May 2023 S1, 15 Apr 2026 S2. Every wording below, oldest first.

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Question 1
16 May 2023 S1
56 $Which from following elements has completely filled 4f orbital at expected ground state configuration?$
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Question 2
15 Apr 2026 S2
33 $Which of the following elements has completely filled 4 f orbital at the expected ground state configuration?$
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