Read the passage carefully and select the best answer to each question out of the given four alternatives. The Amazon basin had long been inhabited by stone age peoples when European expeditions began to explore it. In 1541 a Spanish expedition from Quito, led by Gonzalo Pizarro, ran short of supplies while exploring east of the Andes in present day Peru. Pizarro's cousin Francisco de Orellana volunteered to take sixty men in boats to search for provisions. He floated down the Rio Napo to its confluence with the Amazon near Iquitos in Peru, and then continued down to the mouth of the Amazon. According to the passage, to which river did De Orellana float down in order to reach its confluence with the Amazon?

Introduction / Context:
This question concentrates on a specific factual detail from the historical passage about Francisco de Orellana's journey. The narrative explains how he left the main expedition and travelled by river to reach the Amazon. We must identify the name of the river he followed to the point where it meets the Amazon.

Given Data / Assumptions:

• The passage describes a Spanish expedition under Gonzalo Pizarro that was running out of supplies.
• Francisco de Orellana took sixty men and some boats to look for food.
• He floated down the Rio Napo to its confluence with the Amazon near Iquitos.
• The question asks specifically for the river he floated down.

Concept / Approach:
Again, this is a direct information retrieval question. The approach is simply to locate the sentence mentioning confluence and river names. Once identified, we match the river name with the options. The distractors are other place names from the passage, so we must be careful not to confuse location names like Quito or Belem with the name of the river.

Step-by-Step Solution:
Step 1: Re read the sentence that talks about De Orellana's route.Step 2: Note the phrase floated down the Rio Napo to its confluence with the Amazon.Step 3: Recognise that Rio Napo is the river, while Iquitos and Belem are locations.Step 4: Choose the option that states Rio Napo clearly.

Verification / Alternative check:
To double check, identify all key geographical names in the passage: Quito, Andes, Peru, Rio Napo, Amazon, Iquitos and Belem. Among these, only Rio Napo appears as the river that flows into the Amazon at a confluence that De Orellana reached. This confirms that we have the correct river name.

Why Other Options Are Wrong:
Option A refers vaguely to the river near Belem. The passage mentions Belem as a place where the Portuguese later built a fort, not as the name of the river De Orellana used.
Option B mentions the river at Quito. Quito is the starting city of the expedition, but no river there is named in the passage.
Option D speaks of a river in Peru without naming it, which is too vague and does not match the clear statement in the text.

Common Pitfalls:
Students may confuse place names and river names, especially when many unfamiliar locations are listed. Another common error is to rely on partial memory and only recall that the confluence was near Iquitos in Peru, forgetting the specific river name. Careful re reading of the relevant sentence avoids this mistake.

Final Answer:
The passage states that De Orellana floated down a particular river to reach its confluence with the Amazon, and that river is named Rio Napo. Therefore, the correct answer is To the Rio Napo.