The correct answer is - the desire to profit from the trade of pepper and other spices found in the Indies.
The Dutch, as all the other European colonial countries, were trying to colonize territories that were going to bring big profit to the country. This was the case with the Indies. The Indies were a fertile soil for the production of pepper and other spices, which in Europe were a big deal and the demand for the exotic spices was very big, the prices also very high, so big profit was a guarantee. This made the Dutch to go explore and use the Indies as a place that was going to bring them a big financial benefit.