Final answer:
The most concrete and specific term among the options given is b. 'actress' as it directly refers to a female who performs in movies, television, or theater.
Step-by-step explanation:
The question asks which of the following words is the most concrete and specific: performer, actress, movie star, entertainer, or celebrity. The word actress is the most concrete and specific because it clearly describes a female who acts, specifically in movies, television, or theater. This specificity makes it more concrete than the more general terms such as 'performer' or 'entertainer,' which could refer to a variety of entertainment professionals, and 'celebrity' or 'movie star,' which imply fame but do not necessarily specify the profession.