I’m sure that ACF uses whatever version is packed with WP Core. I honestly don’t know what the min version is for ACF, but I do know that it will run on whatever comes with WP. Personally, I consider that the version that all plugins and themes should run under, but that’s just me, I won’t install a theme or plugin that loads it’s own version of jQuery because you never know when they’ll stop working. There was a recent update in WP 4.5 that was announced here https://make.wordpress.org/core/2016/03/29/jquery-updates-in-wordpress-4-5/
