Which Scenario Is an Example of Social Referencing

Which scenario is an example of social referencing?

A) Jessica sucks her thumb when her brother takes away her favourite doll.
B) Jose smiles when he opens a gift from his grandmother, even though he does not like the new shirt she has given him.
C) Stacey hears her parents arguing and begins to cry.
D) Henry looks up at his mother after he falls and, on seeing her content expression, gets up without crying.