Because the zookeeper let Jeff pet the giraffe's neck, Jeff told his friends that all giraffes were friendly to people. This statement is a logical fallacy called

authority

hasty generalization

popularity

slippery slope

i think c

This statement about the giraffes is a logical fallacy called hasty generalization.

The boy thinks that if one giraffe was friendly to him, that all giraffes are bound to do the same - he is generalizing something that doesn't have to be correct.