Sophie was a dreamer who often made up stories for herself and for others. One possibility might be that she wanted to escape the squalor of daily life with the help of her fantasies. Her encounter with Danny Casey was a made-up story for the sake of catching her brother's attention. Eventually, she got so much engrossed in it that she started to live in the world of fantasy. When Danny Casey did not arrive for the second 'date', she experienced disappointment. However painful and disappointing her fantasy might be, she was not willing to accept reality. Her dreams and disappointments are figments of her imagination.
Study the given molecular structure of double-stranded polynucleotide chain of DNA and answer the questions that follow. 
(a) How many phosphodiester bonds are present in the given double-stranded polynucleotide chain?
(b) How many base pairs are there in each helical turn of double helix structure of DNA? Also write the distance between a base pair in a helix.
(c) In addition to H-bonds, what confers additional stability to the helical structure of DNA?