Explain this one

Explain this one ! 7 1) The percentage of pyridine (C5H5N) that forms pyridinium ion (C5H5N+H) in a 0.10 M aqueous pyridine solution (Kb for C5H5N = 1.7 x is A) 0.77% C) 0.0060% [NEET 11 20161 B) 1.6% D) 0.013%

Dear student
K_b for C5H5N = 1.7 x 10^-9 (given in the question)
pyridine solution concentration is 0.10 M (given in the question)
Therefore, keeping the value in the formulae

Hence, Percentage of pyridine that forms pyridinium ion = 1.30 x 10^-4 x 100 = 0.013%
Hence, option d is correct
Regards