Evaluate the statement ‘‘Earth is known as the Blue Planet’’ in basic astronomy and geography. How should this statement be classified?

Introduction / Context:
Planets in our solar system often have popular nicknames based on their appearance or other characteristics. For example, Mars is commonly called the Red Planet. Earth, when viewed from space, appears predominantly blue due to the presence of vast oceans and the way the atmosphere scatters sunlight. General knowledge questions frequently test recognition of these nicknames.

Given Data / Assumptions:

• The statement being evaluated is that Earth is known as the Blue Planet.
• We assume the standard modern view of planets from space photos and common educational material.
• No calculations are needed; we only need to judge whether the statement is correct or incorrect.
• We also keep in mind that other planets have different colour associations.

Concept / Approach:
A large portion of Earth's surface is covered by liquid water in oceans and seas, which reflects blue light and contributes to a blue appearance in photographs taken from space. In addition, the scattering of sunlight by the atmosphere further enhances the blue colour. For this reason, Earth is often called the Blue Planet in textbooks, documentaries, and popular science. Therefore, the statement is correct.

Step-by-Step Solution:
Step 1: Recall that about three fourths of Earth's surface is covered by oceans.Step 2: Recognise that water and atmospheric scattering give Earth a predominantly blue appearance when viewed from space.Step 3: Compare this with the given statement that Earth is known as the Blue Planet.Step 4: Option A asserts that this statement is correct and matches standard descriptions.Step 5: Options B, C, D, and E contradict well known astronomical facts, so option A is the appropriate classification.

Verification / Alternative check:
Images of Earth taken by astronauts and satellites, such as the famous Blue Marble photograph, clearly show Earth as a bright blue sphere with white clouds. School level astronomy and geography textbooks often use the phrase Blue Planet as a title or caption for Earth. In contrast, Mars is consistently labelled as the Red Planet due to its rusty surface. These independent references confirm that the statement about Earth is correct.

Why Other Options Are Wrong:
Option B confuses Earth with Mars, which is the one commonly called the Red Planet. Option C incorrectly transfers the nickname to the Moon, which actually appears grey or white, not blue. Option D claims that no planet is called blue, ignoring widespread usage of Blue Planet for Earth. Option E suggests that only gas giants fit this description, but while some gas giants like Neptune appear bluish, the phrase Blue Planet in common educational context refers specifically to Earth.

Common Pitfalls:
Some learners mix up planetary nicknames, especially if they have not seen space images recently. Another pitfall is to overthink the question and search for exceptions instead of recognising the straightforward textbook phrase. Remembering the pairing that Earth is the Blue Planet and Mars is the Red Planet makes such questions easy to answer correctly.

Final Answer:
The statement is The statement is correct; Earth is often called the Blue Planet because of its abundant oceans and atmospheric scattering.