Prices of products increase, however, the prices of factor of productions doesn't. Producers will earn more money, more profit. The SRAS will increase.
Production increases and the costs of productions stays the same. However, the price will increase as extra costs will have to be covered (more raw materials, more workers, etc)
Misinterpretation of producers. As they are thinking that they are becoming popular by the increasing of sells, they rise the price.