How are you adjusting reinforcement to clarify for the student when he has selected the very best response on a practice assessment, as opposed to a seductive response that is not the best choice?
What are some reinforcing consequences you can deliver either immediately following the desired behavior or following a practice session– things that this particular student enjoys, wants, seeks out, etc.?
Are you using labeling and social praise to make the contingency between desired behavior and reinforcing consequence clear to the student?
As the student selects the best response, it is important (at least in the initial stages of instruction) to concretely identify why that response was the best choice. So rather than simply saying, "That’s right," you might say, "That’s right. This is the best choice because... These other choices were not the best because..."
What reinforcing consequences can you arrange that are more naturally or intrinsically connected to this targeted behavior?
When the student selects the best response, work to clarify the relevance of that response to the student’s real life. For example, if the question relates to a social communication skill that impacts overall teamwork, point to the situations that the student encounters every day (in school, in the community, etc.) where a similar issue would arise.