Which one of the following paper-pencil assessments is most likely to have a reliability problem when the teacher scores students' responses?
a) Ms. Gibbons asks students to describe the "first Thanksgiving" in a short essay.
b) Mr. Hammond gives 50 true-false questions about the geography of Russia.
c) Ms. Sonnenschein administers a 30-item multiple-choice test about invertebrates.
d) Mr. Strong gives a 10-word spelling test.