Can't create assets folder in android studio

I'm trying to create an assets folder in android studio but the option is grayed out! [1]: https://i.sstatic.net/kbLO4.png

you have set your minSdkVersion to less than 16 in build.gradle (:app) go and search minSdkVersion and set it to minimum 16 I suggest set 21

defaultConfig {
    minSdkVersion 21
}