Answer: For the given process it is true that the balloon has a net charge on it, but the wall may be neutral (have no net charge).
Explanation:
When we tend to rub a balloon against a woolen sweater then it is possible that the balloon might stick to the wall. This might be due to the increase in number of electrons on the balloon and the wall gets positively charged.
Since, opposite charges tend to attract each other hence, the balloon will stick to the wall.
A neutral object also tends to acquire a certain charge when it is rubbed by a charged object.
Therefore, we can conclude that the balloon has a net charge on it, but the wall may be neutral (have no net charge).