Answer: D)Each of the conference rooms has a computer display.
Explanation: Subject-verb agreement means the subject and verb must have the same number (both singular or both plural). With the word "each" we can have different cases: if "each" is placed before a singular noun, then the verb must be singular; if "each" is placed after a plural noun, then the verb must be plural; and if we have the phrase "each of" the verb should be singular. In the given sentence we have the third case, therefore the verb should be in singular "has:" Each of the conference rooms has a computer display.
