annihilation : obliteration
if the choices were:
strategy : tactics
sensation : numbness
deliberation : impulsiveness
endeavor : quit
Then the word pair that would best complete the analogy is:
STRATEGY : TACTICS
Annihilation and obliteration are synonymous. In fact, annihilation is defined as complete destruction or complete obliteration. Obliteration is defined as total destruction.
Strategy and tactics are also synonymous. They both mean a system or mode of procedure or a plan of action.
The rest of the choices are antonyms.