What is the か for after だから here


新宿区立新宿中央公園は西新宿、都会のど真ん中にある公園。 ジョギングブームだからか、一昔前まではなかったジョギングコースの案内板があり、
ここでジョギングをする人たちもちらほら。

I cant seem to wrap my head around だからか here, what exactly is the か and what
is it trying to emphasize? Here is my attempt at the translation

> In the west of Shinjuku is Shinjuku central park. It is located in the
> center of the city. Even before this was a jogging course there were
> direction boards, and now you will find joggers here and there at the park
> running.

I hope I understood somewhat correctly, please feel to correct any mistakes.
Thank you.




> 「～～だからか」

means:

> "most likely because of ~~"

It expresses the speaker's (best) guess or inference as to the reason for
something. The speaker is pretty sure of the reason but is just not 100% on
it, so he attaches the question marker 「か」.

> "Most likely because of the popularity of jogging, there is now a direction
> board for the jogging courses, which did not exist a while back, and you
> will find joggers here and there at the park running."




> 「～～だからか」

means:

> "most likely because of ~~"

It expresses the speaker's (best) guess or inference as to the reason for
something. The speaker is pretty sure of the reason but is just not 100% on
it, so he attaches the question marker 「か」.

> "Most likely because of the popularity of jogging, there is now a direction
> board for the jogging courses, which did not exist a while back, and you
> will find joggers here and there at the park running."

