Final answer:
A 10-month-old infant can crawl and sit unaided but typically cannot walk unaided; walking without assistance is a milestone usually reached closer to the child's first birthday.
Step-by-step explanation:
With respect to gross motor skills, a 10-month-old infant should be able to do all of the following except walk unaided. By the age of ten months, an infant typically has the ability to wiggle, crawl, and sit unsupported. It is typical for them to exhibit the motor skills to search for a dropped toy and grasp it using a pincer grasp, but walking unaided usually comes a bit later in their development.
Most toddlers begin to walk with assistance by their first birthday and may manage a few unaided steps by one year old, as they progress in developing their motor skills. This milestone is often reached anytime between nine months to a year and a half. Therefore, the correct answer to the question is ‘a. Walk unaided’.