Exploration (people being able to explore unknown continents and countries) was aided by astronomy (the stars showed direction) and the development of what instrument? Is it the compass?

Since the compass is magnetic and has nothing to do with astronomy, I think the instrument you want is explained here:

http://www.astrolabes.org/

http://en.wikipedia.org/wiki/Sextant

(Compasses have to do with Earth's magnetic fields: http://en.wikipedia.org/wiki/Compass )

Yes, you are correct! The development of the compass was a crucial factor in aiding exploration. The compass is an instrument that uses the Earth's magnetic field to determine direction. It consists of a magnetized needle that aligns itself with the Earth's magnetic field, pointing towards the Earth's magnetic north. By using a compass, explorers could navigate across vast oceans and unfamiliar terrains, as the needle would always point towards the Earth's magnetic north, providing a reliable sense of direction.

To arrive at this answer, you could have followed the following logical steps:

1. Understand the context: In this case, the context is about exploration and the aid of astronomy.
2. Identify the role of astronomy: By reviewing historical accounts, you may have discovered that early explorers used astronomy, particularly celestial objects like stars, to navigate and determine their direction on their journeys.
3. Consider other aids for exploration: Think about other instruments or tools that could have helped explorers navigate uncharted territories.
4. Identify the most crucial instrument: When considering the available options, the compass stands out as a vital navigational tool. It not only complements astronomical observations but also provides a reliable direction independent of daytime or weather conditions.
5. Make a conclusion: Based on the above analysis, you can confidently conclude that the compass played a significant role in aiding exploration alongside astronomy.

Exploring the historical context and drawing connections between different factors are essential steps in finding the right answer.