The answer is letter C.
Between months 9 and 10, babies have the ability to already move
themselves around. Their curiosity to learn things is what drives them to
experiment in their process of learning. During this stage the baby
can already crawl and pull himself up in a standing position and he might be
holding on to furniture sets to support this movement. Towards the end of these months the baby may
start to climb on things like stairs and foot stools.
