Hey everyone ! I would like to know why this image was rejected by Adobe Stock.

The above image isn't B&W. This is B&W, which is not recommended!

The shadows are also under exposed and it is black and white.

You've also converted it to duotone, which is not permitted by Adobe stock,

Hi,

I would say also the overexposed Sky and maybe also that the Skydiver are a little bit small.

Before you submit, please review the submission guidelines carefully and compare your work with other Stock inventory. To be accepted, your work should be as good or better than what's already represented in your keyword category.

https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html
https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html

https://helpx.adobe.com/stock/contributor/help/photography-illustrations.html
https://helpx.adobe.com/stock/how-to/tips-stock-image-acceptance.html

Hope that helps.