Q. 56 Language L1 is polynomial time reducible to language L2. Language L3 is polynomial time reducible to L2, which in turn is polynomial time reducible to language L4. Which of the following is/are True?
I. If L4 ∈ P, L2 ∈ P II. If L1 ∈ P or L3 ∈ P, then L2 ∈ P III. L1 ∈ P, if and only if L3 ∈ P IV. If L4 ∈ P, then L1 ∈ P and L3 ∈ P
(A) II only
(B) III only
(C) I and IV only
(D) I only
Answer: (C)
Explanation: