Anchor sinking effect refers to the fact that when people make judgments about something, they are susceptible to the first impression or first information, which fixes people's thoughts somewhere like an anchor sinking into the sea. The first impression and preconceivedness are its manifestations in social life.
The option "The boy invited the girl he liked and said: Shall we hang out? The girl felt that it was natural to refuse, and if she agreed, it will be too proactive, so she said: Next time. The boy thought the girl had no intention of interacting with him" is not anchor sinking effect according to the above definition.