Question marks: "how can I escape from this poverty?"

[Bml]

Could anyone tell me if I need to use a question mark in a rhetorical question such as this?
He asked that most worrying of questions, “how can I escape from this poverty?”

[Mister Micawber]

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Yes, a rhetorical question is still a question.

He asked that most worrying of questions, “How can I escape from this poverty?”
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Native English teacher at Mister Micawber's

[Bml]

Lived in Oxford England the centre of the civilised world for most of my life and I had to go to Japan for an English grammar answer. Many thanks.