Explanation:

- Option 1: Martinet

- Meaning: A person who demands strict discipline.

- Usage: Often used to describe someone who is very strict or adherent to rules.

- Option 2: Phlegmatic

- Meaning: Having an unemotional and stolidly calm disposition.

- Usage: Describes someone who is not easily excited to action or emotion.

- Option 3: Congenital

- Meaning: A condition present from birth.

- Usage: Usually used in medical contexts to describe conditions or traits.

- Option 4: Occular

- Correct Spelling: Ocular

- Meaning: Related to the eye or vision.

- Explanation: The correct spelling does not have the double 'c'.

Therefore, the incorrectly spelt word is indeed Option 4: Occular.

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