In this error spotting question on comparison and degree, identify the incorrect part in the sentence: "Of the many problems that confront the leaders of the world, none are of grave consequence than the problem of saving the normal human race from extinction."

Introduction / Context:
This question evaluates understanding of comparative degree and subject verb agreement. The sentence is "Of the many problems that confront the leaders of the world, none are of grave consequence than the problem of saving the normal human race from extinction." Candidates must identify the incorrect fragment. The sentence intends to say that one particular problem is more serious than all others, so it should use a comparative form and appropriate verb agreement with "none".

Given Data / Assumptions:

• The sentence compares many global problems with the problem of saving the human race from extinction.
• Segment (a) is "Of the many problems that confront the leaders of the world".
• Segment (b) is "none are of grave consequence than the problem of saving".
• Segment (c) is "the normal human race from extinction."
• Segment (d) is "No error".
• We assume standard formal English usage with correct comparative structures.

Concept / Approach:
The word "none" is usually treated as singular in formal writing when it means "not one". In this sentence, it refers to "none of the many problems". Therefore, the verb should be singular: "none is". In addition, when comparing degrees of seriousness, English uses comparative degree: "graver" or "more grave" rather than simply "grave". The correct expression should be "none is of graver consequence than the problem of saving the human race from extinction." Segment (b) therefore contains two issues, and this makes it the incorrect fragment.

Step-by-Step Solution:
Step 1: Understand the meaning: among many problems, the problem of saving the human race is the most serious. Step 2: Look at the structure beginning with "Of the many problems that confront the leaders of the world"; this part correctly introduces a group. Step 3: Focus on the phrase "none are of grave consequence than". Step 4: Recall that "none" is often singular in formal context and should normally take "is" when it means "not one". Step 5: Recognise that a comparison should use comparative degree: "of graver consequence than" or "of more grave consequence than". Step 6: Conclude that the corrected version is "none is of graver consequence than", so segment (b) is the incorrect part.

Verification / Alternative check:
Rewrite the sentence as it should appear: "Of the many problems that confront the leaders of the world, none is of graver consequence than the problem of saving the human race from extinction." Now the subject "none" agrees with the singular verb "is", and the phrase "of graver consequence than" clearly shows comparative degree. This version reads smoothly and matches standard usage. Therefore, the issues in segment (b) are confirmed, while segments (a) and (c) support the meaning without error.

Why Other Options Are Wrong:
Option (a) correctly introduces the set of "many problems" and uses the present tense "confront" appropriately. Option (c) "the normal human race from extinction." naturally expresses the object of the problem, although many writers would omit the word "normal". Option (d) "No error" is not correct because segment (b) clearly needs modification for agreement and comparative degree.

Common Pitfalls:
Many learners believe that "none" is always plural and must take "are". In fact, usage guides explain that "none" can be either singular or plural depending on context. When the meaning is "not one", singular is more appropriate. Another common mistake is forgetting to change the adjective to comparative form in sentences with "than". For example, writing "more big than" instead of "bigger than", or "grave than" instead of "graver than". Always check that adjectives used in comparisons are in comparative form or are accompanied by "more" or "less".

Final Answer:
The incorrect part is option (b) "none are of grave consequence than the problem of saving". It should be "none is of graver consequence than the problem of saving". Therefore, the correct answer is "none are of grave consequence than the problem of saving".