Letting link bold when is clicked on Ruby

I am working on this .erb file and I have a method that returns a map with links. What I want here is to let the link bold when you click on it. So the web page will be something like that:

A | B | C | D

and if I click on D will send me to that path and D will be bold

A | B | C | D

<%= template.myMethod.map{|link| "|#{link}"}.join("")%>

Thank you