All you have to do is to spot the aromatic rings in these compounds. It may not be as easy as you think and you should give reasons for questionable decisions .
 

Truly aromatic rings are marked with bold lines. Thyroxine has two benzene rings- obviously aromatic and that's that. Aklavinone also has two aromatic benzene rings and we might argue about ring 2. It has four electrons as drawn, and you might think that you could push electrons round from the OH groups to give ring 2 six electrons as well. But if you try it, you'll find you can't .

Colchicine has one benzene ring and a seven-membered conjugated ring with six electrons in double bonds (don't count the carbonyl electrons as they are out of the ring). It perhaps looks more aromatic if you delocalize the electrons and represent in as a zwitterion. Either representation is fine.

Methoxatin has one benzene ring and one pyrrole ring-an example of an aromatic compound with a five-membered ring. The six electrons come from two double bonds and the lone pair on the nitrogen atom. The middle ring is not aromatic-even if you try drawing other delocalized structures, you can never get six electrons into this ring.