Read the following excerpt and answer the question that follows.
I dive down, driving with my fin, slipping through the water, sinuous as a seal. A readout in the corner of my helmet shows my depth: 2500 m. I’m tempted to kick harder but know I would just churn water and waste energy. I stretch my arms forward, hands clasped together, and focus on being one with the water, a streamlined sliver in the dark deep. I’m fast and beautiful and graceful and terrible.
Which of the following phrases from text helps define the word sinuous as it is used in this excerpt?
in the dark deep
fast and beautiful and graceful
tempted to kick harder
churn water and waste energy