Letter D would be correct.
The beginning of the European colonization of Southeast Asia occurred along the 16th and 17th Centuries and was marked by a heavy dispute between the great marine traders. The firsts to arrive were the Dutch, Portuguese and Spanish, followed by the French and British spice traders. They all soon engaged in eliminating each other through acquiring strategic locations and production centers. Later on, along the 17th and 18th centuries, they focused on dominating ports along the maritime routes, what also allowed them to levy taxes and control prices of the Asian commodities under their control.
Holmes wanted to look at the hotel register to make sure if the man was staying at their hotel. He came to know that he was not. There were other people staying there.
Sir Arthur Conan Doyle wrote "The Hound of the Baskervilles" which is a crime novel and the main character in the novel is the famous detective Sherlock Holmes.
I don't know where it is but it is important because it has a lot of water and most people needs it