There is no "Ignore / Add to exclusions" choice in the drop down. See screenshot.
Yes, there is a "Report false positive" link (in the picture it is hidden under the drop down list), but that is not really the same as Ignore.
For instance, I would like Avast real time detection to ignore a certain file (a PUP), but it is actually a PUP, not a false positive.
And, no, disabling PUP detection altogether is not the same, either.