How to display image on condition that a selection has been made

I have a custom post type ‘Holidays’ and a custom field (created using Advanced Custom Fields) called ‘activity_rating’. The activity_rating field is a select dropdown with values 1 to 5.

If the holiday has been rated as very easy (1) then I would like to display a certain image (1 star), if the holiday has been chosen to be easy (2) then I would like a different image to be displayed (2 stars) etc all the way to 5 (very difficult).

So far I have this from ACF’s website but am struggling as to add/how edit

<?php

/*
*  Conditional statement (Single Value)
*/

if(get_field('activity_rating') == "1")
{
    //...
}

Any ideas very much appreciate!