You have all heard about the CYK algorithm. The algorithm has a running time of O (ny) Consider the following context-free grammar, which is in, of course, CNF. S BCCD B CBC C + DDC DBC | We want to figure out whether the string w=bcbbb can be derived in the grammar above. To do this, we will use the CYK algorithm. The CYK table is given below for your convenience. X1,5 X2,5 X2, 4 X1,4 X1,3 X1,2 X1,1 X2,3 X3,5 X3, 4 X3, 3 X4,5 X2,2 X4,4 X5,5 W1 W2 W3 W4 W5 1. Which of the following variables should be in X3,4? S B D None of the above 2. Which of the following variables should be in X1,3? S C D None of the above 3. Which of the following variables should be in X1,5? B D None of the above 4. Can w be derived in the grammar above? Yes No