Correct option is (A) 10/9
\(\because\) Krishna read in 1 hour = \(\frac{1}{3}\) part of a book
\(\therefore\) Krishna read in \(3\frac{1}{3}\) hours = \(3\frac{1}{3}\) \(\times\) \(\frac{1}{3}\) part of that book
= \(\frac{3\times3+1}{3}\) \(\times\) \(\frac{1}{3}\)
= \(\frac{10}{3}\) \(\times\) \(\frac{1}{3}\) = \(\frac{10}9\) part of the book.