Four pair of words are given below out of which three are alike in some manner and one pair is different. Which is different from the rest?

Option 2 : Paddy : Husk

The relation is:

1) Student : Scholar → A student can be described as a learner especially one enrolled in a school or college whereas a scholar denotes a learned person with profound knowledge of any specific subject. 

2) Paddy : Husk → A paddy or a paddy field is a field that is kept flooded with water and is used for growing rice, while the dry outer covering of rice is called husk.

3) Soldier : Warrior → A warrior is (especially in former times) a brave or experienced soldier or fighter; a soldier is a person who serves in an army.

4) Politician : Leader → A politician is a person active in party politics. A leader is the person who leads or commands a group, organization, or country.

In all pairs except ‘Paddy : Husk’, one is the best version of another or we can say the second term is used in the most respectable way to denote the first term, while there is no such relation between ‘Paddy : Husk’.

Hence, ‘Paddy : Husk’ is the odd one out.

Option 2 : Stamps : Phillumenist

Numismatics is the study or collection of currency, including coins, tokens, paper money etc

Bibliophilist is a collector of books.

Deltiologist is the person who collects postcards.

But the person who collects stamps called as Philatelist not Phillumenist.

Phillumenist is the person who collects matchbox or matchbook labels.