Task: Question Answering
Input (English): Which of the following regular expressions is equivalent to (describes the same set of strings as) (a* + b)*(c + d)?
(A)a*(c + d)+ b(c + d) (B)a*(c + d)* + b(c + d)* (C)a*(c + d)+ b*(c + d) (D)(a + b)*c +(a + b)*d
Output (English): D