Which developmental milestone is commonly observed in toddlers?

The developmental milestone of asserting independence is indeed a hallmark of toddler behavior. During this stage, typically between the ages of 1 and 3 years, children start to explore their autonomy and make choices about their environment. This can manifest through behaviors such as saying "no," wanting to do things by themselves, and showing preferences for certain activities or toys.

As toddlers become more mobile and gain control over their bodies, they often wish to exert their newfound independence. Their desire to explore, learn, and engage with the world around them showcases their growing autonomy. This can also lead to situations where they test limits, which is a normal part of development as they begin to understand social boundaries.

The other options represent important developmental skills, but they occur at different stages or are not as universally recognized as milestones during toddlerhood. Beginning to walk, for example, is a critical physical development milestone but is usually observed in the earlier stages of toddlerhood. Learning to count and engaging in fantasy play typically develop later, as language and cognitive abilities continue to evolve beyond the toddler years.