This will give you the following interface. Select JPEG, then check Optimized and Embed Color Profile (which should always be sRGB, by the way, as per Adobe’s requirements), then input the highest Quality number that you can while keeping the result under 5M (lower left corner). You can probably create an Action that will do the bulk of these steps for you.
Adobe Community Expert | If you can't fix it, hide it; if you can't hide it, delete it.
we need to see the full image. Still, the shadow of the photographer in the photo is enough to reject it. Here is a small Windows program that I wrote to downsize images so that they can be uploaded here in the forum. Photo Downsizer.zip I offer no guarantees with the program.
Try not to crop. Composition can be a common reason for rejection. Instead, reduce the entire image as little as possible as a jpg (quality 8 usually does the trick) to keep it under 5MB. I know, it’s a pain. The limit used to be 10MB and even then, it was sometimes difficult to post an image at the size originally submitted for review.
Adobe Community Expert | If you can't fix it, hide it; if you can't hide it, delete it.