Synonyms

Manmohan Singh's (P.M.)  political image is immaculately clean.

His Crime tantamount to contempt of court.

Dubious means doubtful, uncertain, or questionable. Doubtful is a direct synonym. Duplicate means a copy, dutiful means obedient, and neither is related to dubious.

Mankind has been plagued by various ailments so man has worked hard to find cure for such afflictions.

Guru Nanak Dev ji emancipated women by speaking in favour of them.

Judges should exercise discretion to catch the real culprits.

His father died because of Emphysema.

country can progress only if its politicians avoid embezzlement.

The murderer has tampered with the evidence ,so could not be proved guilty.

It becomes Imperative for all of us to reduce global warming.

Reema has done post graduation in epistemology.

Most couples feel they are Incompatible so divorces are on rise.

Many Indians are coming back from foreign lands because of nostalgia

As a verb, 'object' means to express disagreement or opposition. The closest synonym given is 'purpose' (as in 'I object to this' meaning 'I have a purpose/intention to oppose this'). However, 'object' as a noun means a material thing, making this context-dependent.

Puzzled means confused or unable to understand something clearly, making it the correct synonym. Doctrine refers to a set of beliefs, proof is evidence of truth, and try means to attempt - none relate to being confused.