Find the part containing the error; choose ‘‘No error’’ if the sentence is correct. Sentence: His speech was judged by many as one of the most important speech given in the function.

Introduction / Context:
Here the test is on number agreement after the quantifier ‘‘one of the …’’ which must be followed by a plural noun. This is a very common exam pattern.

Given Data / Assumptions:

• Determiner phrase: ‘‘one of the …’’
• Noun used: ‘‘speech’’ (singular) after ‘‘one of the most important’’
• Setting: a function where speeches were delivered

Concept / Approach:
When a noun phrase begins with ‘‘one of the,’’ the head countable noun that follows must be plural: ‘‘one of the best speeches,’’ ‘‘one of the finest books.’’ The verb earlier in the sentence relates to ‘‘His speech’’ and is correct; the error is purely in noun number after the quantifier.

Step-by-Step Solution:
Locate the quantifier: ‘‘one of the …’’Ensure plural noun form after it: change ‘‘speech’’ → ‘‘speeches.’’Corrected segment: ‘‘as one of the most important speeches …’’

Verification / Alternative check:
Paraphrase: Many people judged his speech to be among the most important speeches at the function. ‘‘Among’’ similarly requires a plural set, reinforcing the need for ‘‘speeches.’’

Why Other Options Are Wrong:
A is fine; B is a proper passive agent phrase; D correctly adds a reduced relative clause ‘‘given …’’ modifying ‘‘speeches.’’ Only C misuses singular after ‘‘one of the.’’

Common Pitfalls:
Forgetting the plural after ‘‘one of the …’’; trying to force agreement with the earlier ‘‘His speech’’ and accidentally making the set noun singular.

Final Answer:
as one of the most important speech