The sentence talks about stranger anxiety, that is the anxiousness children exhibit at the presence of strangers and how it can cause problems when children START doing ‘something’. Socialize is the apt word for the first blank and it means ‘mix socially with others. In the second blank, hesitant means ‘tentative, unsure, or slow in acting or speaking’. The MEANINGS of the other WORDS are:

Fight=> take part in a violent struggle involving the exchange of physical blows

Precipitate=> cause an event or situation, typically one that is undesirable to HAPPEN suddenly, unexpectedly, or prematurely.

Faint=> feeling weak and dizzy and close to losing consciousness

Cranky=> bad-tempered, irritable

Doodle=> scribbling absent-mindedly

Scared=> frightened

Deafen=> cause an event or situation, typically one that is undesirable to happen suddenly, unexpectedly, or prematurely

Difficult=> needing much effort or skill to accomplish, deal with, or understand

Hence the correct ANSWER is option 2.