Final answer:
Toddlers aged 2-3 years old are at a stage where their gross and fine motor skills are developing rapidly. It is a suitable time to introduce them to a balance bike.
Step-by-step explanation:
Toddlers aged 2-3 years old are at a stage where their gross and fine motor skills are developing rapidly. At this age, they have the ability to climb stairs, handle small objects, and build towers of blocks. They are also improving their balance and coordination, which makes it a suitable time to introduce them to a balance bike.