Is a sentence ending with "か……。" a question or a questionative statement?

Question

I came across the following line inside a Japanese book I'm reading.

しかし、　アインにツヴァイか……。

My understanding of the line is different depending on whether it would be a question (because of the か),.

For example, "However, why Ein and Zwei...?"

Or would it be a ellipsis statement, (idk what the proper terminology is for this kind of statement) where the question is implied through the contemplative format of the sentence, but not stated outright:

Example: "However, Ein and Zwei..."

TDLR: is a sentence ending with "か……。" a question or a questionative statement?

Answer 1

The correct term is rhetorical question, and yes, in this case it is a rhetorical question. Also there is no "why" in the Japanese sentence.

Japanese people often use か like that, especially to confirm what has already been said, for example:

A: 俺だ！ = It's me!

B: お前か... = So it's you (huh)...