From the passage, we see that the author highlights the simplicity of the book’s language. It is written in plain English, making it suitable for children of all age groups, hence (i).
The passage directly states that short and simple sentences add to the simplicity of the book, so (ii).
It also notes that mischievous children are actually sensitive and loving, which explains (iii).
Finally, R.K. Narayan is described as a “literary genius,” which completes (iv). All answers are directly supported by lines from the text.