Suppose the letters a,b,c,d,e,f have probabilities of 1/2, 1/4, 1/8, 1/16, 1/32, 1/32 respectively. Which of the following is the Huffman code for the letter a,b,c,d,e,f? Please show how is the Huffman tree, so that you can determine one of the options below.
a. 0, 10, 110, 1110, 11110, 11111
b. 11, 10, 01, 001, 0001, 0000
c. 11, 10, 011, 010, 001, 000
d. 110, 100, 010, 000, 001, 111