I am using a template override to show content depending on the output of certain extrafields. I'm trying to write an IF statement that shows a section of content only if the user has included a specific option from a multi-select list.

I can write IF statements if an extrafield equals or does not equal a value, but I can't work out how to say "show content IF list INCLUDES this specific value". The content needs to show whether they choose just that option in the list, or that option plus other options as well.

So far I have tried amongst other things:

<?php if(strpos($this->item->extraFields->ExtraField1->value , "Option1")): ?>
Show me!
<?php endif; ?>