La personne dont(?) je pense me rend hereux

Question

Why are only "a qui" and "a laquelle" accepted as answers, while "dont" isn't?

Accepted Answer

Hi Ethan, 
The relative pronoun 'dont' isn't accepted because it is wrong here.
You can only say -
La personne à qui /à laquelle je pense ...
The verb is 
penser à quelqu'un 
You could use 'dont' if the verb was followed by 'de'-

La chose dont je suis consciente c'est ...
La personne dont je parle ...

parler de = to speak about someone
être conscient/e de quelque chose = to be aware of something 
I hope this helps!

Answer

Hi Ethan,The verb is penser à    --> to think about (in the sense of "in one's mind")Therefore "dont" is not appropriate because it translates to "of who/whom""Penser de"   carries the sense of  "to have an opinion of"Jim