The correct answer is: B. nomads.
A nomad is a person who has no permanent home and moves from place to place in search of food, water, and grazing land for their animals. Nomads typically live in tents or other portable shelters and travel in small groups. Their lives are often difficult and uncertain, as they are constantly exposed to the elements and the dangers of the natural world.
Travelers, on the other hand, are people who move from place to place for pleasure or business. They typically stay in hotels or other temporary accommodations and have a more stable lifestyle than nomads.
Sailors are people who work on ships. They may be involved in a variety of activities, such as fishing, cargo transportation, or tourism. Sailors typically live on board their ships for extended periods of time and have a unique and challenging lifestyle.
Tourists are people who travel for pleasure. They typically stay in hotels or other tourist accommodations and participate in a variety of activities, such as sightseeing, shopping, and dining. Tourists typically have a more relaxed and leisurely lifestyle than nomads, travelers, or sailors.
In conclusion, the correct answer to the question “It is a rugged restless and uncertain existence that the . . . . . . . . lead” is B. nomads. Nomads are people who have no permanent home and move from place to place in search of food, water, and grazing land for their animals. Their lives are often difficult and uncertain, as they are constantly exposed to the elements and the dangers of the natural world.