Question: Which example reflects a secondary circular reaction? A 1-month-old infant stares at a mobile suspended over her crib. A 12-month-old toddler licks a bar of soap to learn what it tastes like. Realizing that rattles make a noise, a 4-month-old infant laughs with delight when his father puts a rattle in his hand. A 2-month-old infant sucks a pacifier.