The easiest way to achieve this would be to have an if statement in code that retrieves the image from a url based on the selected option. ie:
<?php
$image_url = "";
$option = get_field("selected_option");
if($option=="option1"){
$image_url = "image1.jpg";
}else if($option=="option2"){
$image_url = "image2.jpg";
}
?>
<img src="<?php echo $image_url; ?>" alt="Image">
