"if one wants to determine the effectiveness of a stimulus as a reinforcer relative to another stimulus, which assessment method would be most appropriate? "

Paired-stimulus assessment.

Explanation:

It is a type of assessment under which a teacher creates a ranking of children preferences. It is a trail based assessment under which in each trail two items are presented to child and teacher asks the child to make the choice. In every trail teacher present the child two items until every item gets paired with other in a round-robin style. However, it is long process of assessment because it require more trails to be conducted. But it is very helpful in the assessment of children who engage in problem behavior and when their preferred are taken away from them.

if you have to make a general question and respond to your thoughts, then this isn't really a question someone can you on. read the passage, form your question, and answer using your thoughts. no one else can understand how you interpreted this text if you don't tell us.

the answer is d.index