<p>Intimacy, love, and marriage are three different, if interrelated subjects
a) different, if interrelated, subjects
b) interrelated usbjects, being, however, different
c) different subjects, wereas they are interrelated
d) different subjects when interrelated
e) subjects that are different although being interrelated</p>
<p>I suspect you may not quite know the meaning of the word whereas. It is a subordinating conjunction that means something along the lines of “in contrast to the fact that,” or sometimes “since it is the case that.”</p>