Final answer:
The word 'skeptical' is a synonym for 'incredulous,' as both convey a sense of doubt or disbelief. Other options like fabulous, fascinating, and furious represent different emotions or characteristics and do not match the meaning of incredulous.
Step-by-step explanation:
When looking for a synonym for incredulous, we are searching for a word that means disbelieving or skeptical. Among the options provided, the word that best fits the meaning of incredulous is skeptical. This choice aligns with the feeling of doubt or a lack of conviction.
Option (b) fabulous, option (c) fascinating, and option (d) furious do not align with the meaning of incredulous. These words are associated with different emotions or characteristics. Fabulous is related to being amazing, fascinating to being extremely interesting, and furious to being extremely angry. None of these has the same connotation of doubting belief as incredulous or skeptical does.