Read the reading below carefully, and then complete it with the best option A, B, C or D given below:
For Nigel Portman, a love of traveling began with what's called a “gap year”.
In common with many other British teenagers, he chose to take a year out before (1) ______ to study for his degree. After doing various jobs to raise some money, he left home to gain some experience of living in different cultures, visiting America and Asia. The more adventurous the young person, the (2) ______ the challenge they are likely to set themselves for the gap year, and for some, like Nigel, it can result in a thirst for adventure. Now that his university course has (3) ______ to an end, Nigel is just about to leave on a three-year trip that will take him all around the world. What's more, he plans to make the whole journey using only means of transport which are powered by natural energy. In other words, he'll be (4) ______ mostly on bicycles and his own legs; and when there's an ocean to cross, he won't be taking a short cut by climbing aboard a plane, he'll be joining the crew of a sailing ship instead. As well as doing some mountain climbing and other outdoor pursuits along the way, Nigel hopes to (5) ______ on to the people he meets the environmental message that lies behind the whole idea.

he chose to take a year out before (1) ______ to study for his degree.