The answer is definitely d., I remember reading the book.
I need to read the book first before i answer your question
What's the question? or what do u need help with?
Every gerund/participle ends in -ing, so you can know for sure that the answer is one of these two. Since here <em>turning </em>is used with an adverbial function (that is, it is basically an adverb - it tells us WHEN Kate bumped into David), the correct answer is B) participial.
