Please answer the following question: Read the following article and select the best answer. Article: When people hear that I'm the youngest person to row solo across the Atlantic Ocean, they all have the same question: How did a 22-year old woman row a 19-foot boat for 70 days through high winds and crashing waves? Well, the biggest difficulty for me wasn't physical. By the time I decided to do the ocean row, I had already biked 3,300 miles cross-country, run across the Mojave Desert, and swum the 325-mile length of the Allegheny River. No, the tough part would be mental: How would I handle the loneliness, the boredom of the vast sea? I set off on January 3, 2010. I set my sights on getting past the quarter-way mark, which would take about 20 days. Day 20, January 22, was gray and cloudy. _ I was suffering from terrible loneliness. I hadn't seen landing over two weeks. Every day was beginning to feel the same. Eating, rowing, sleeping, watch the sky, watch the ocean. Then, around sunset, I saw something move on the horizon. They were dolphins! They circled my boat. Suddenly I felt so grateful. They had come to help me celebrate, just when I needed them. I rowed at full strength for the next 20 minutes with the dolphins around. By the time we went our separate ways, I was no longer lonely. Better yet, I knew I would be okay. I did make it, all 2,817 miles. I hit the coast of Guyana, South America, on March 14, after 70 days and five hours at sea. My ocean row raised $70,000 for the Blue Planet Run Foundation, which funds drinking water programs around the world. I know some athletes spend the entire journey imagining the end, and that helps them get through. But for me, the secret is to focus on the moment, where you experience the personal growth -- those moments of awareness of being connected to the sun, the weather, and the waves. And, on the best day of my life, those dolphins, which freed myself from terrible loneliness. Question: Which is the step taken as part of preparation for the tough row? - swimming the 325-mile length of the river - answering the same question raised by people - running 3,300 miles cross-country - biking across the Mojave Desert
Answer:
swimming the 325-mile length of the river