The probability distribution of a random variable X is : | X | 0 | 1 | 2 | 3 | 4 | |---|---|---|---|---|---| | P(X) | 0.1 | k | 2k | k | 0.1 | where k is some unknown constant. The probability that the random variable X takes the value 2 is : (A) $\frac{1}{5}$ (B) $\frac{2}{5}$ (C) $\frac{4}{5}$ (D) 1