In this error-spotting sentence about an office building, identify the part that contains an error, if any: Our office building comprises seven floors and a restaurant at the top in an area of about eight hundred sq. metres.

Introduction / Context:
This is another error-spotting question that tests your understanding of vocabulary, prepositions, and sentence structure. The sentence given is: “Our office building comprises (1)/ seven floors and a restaurant at the top in an (2)/ area of about eight hundred sq. metres. (3)/ No Error (4)”. You must locate the segment with a grammatical or usage error or confirm that the sentence is fully correct.

Given Data / Assumptions:

• Part (1): “Our office building comprises”
• Part (2): “seven floors and a restaurant at the top in an”
• Part (3): “area of about eight hundred sq. metres.”
• Part (4): “No Error”
• The sentence describes the structure and total area of an office building.

Concept / Approach:
The main points to check are: correct use of the verb “comprise”, the noun phrase “seven floors and a restaurant at the top”, the preposition and article combination “in an area”, and the expression “about eight hundred sq. metres”. The verb “comprise” means “consist of” or “be made up of”. The standard and increasingly preferred pattern is “A comprises B and C”, without any preposition after “comprises”. The object of the verb can be a list of elements. The expression “in an area of about eight hundred square metres” is also idiomatic and grammatically acceptable.

Step-by-Step Solution:
Step 1: Examine part (1) “Our office building comprises”. This correctly introduces the subject and uses the verb “comprises” in the sense of “consists of”. There is no need for “of” after “comprises” here. Step 2: Look at part (2) “seven floors and a restaurant at the top in an”. This part lists the components (seven floors and a restaurant) and begins the prepositional phrase “in an area”. The construction is acceptable. Step 3: Look at part (3) “area of about eight hundred sq. metres.” The phrase “an area of about eight hundred square metres” is correctly formed: article + noun + preposition + approximate quantity + unit of measure. Step 4: When the three parts are read together—“Our office building comprises seven floors and a restaurant at the top in an area of about eight hundred sq. metres.”—the sentence is meaningful and grammatically sound. Step 5: Because there is no clear grammatical or usage error in any of the first three parts, the correct answer must be “No Error”.

Verification / Alternative check:
We can compare the sentence with other correct uses of “comprise”: “The committee comprises ten members”, “The bouquet comprises roses, lilies and orchids”, “The course comprises three written papers and a viva”. In each case, “comprises” directly takes the objects without “of”. Our sentence follows the same pattern. If we changed it to “comprises of seven floors…”, it would be considered incorrect in formal English. The rest of the structure, including “in an area of about eight hundred square metres”, is standard.

Why Other Options Are Wrong:
Part (1): correct use of “comprises” as a transitive verb taking a list of components. Part (2): correctly joins “seven floors” with “a restaurant at the top” and starts the prepositional phrase without any incorrect preposition. Part (3): expresses the size of the building’s footprint or floor area correctly using “in an area of about eight hundred sq. metres”. Therefore, there is no grammatical error in any of these parts.

Common Pitfalls:
Many learners have seen “is comprised of” in everyday usage and mistakenly think that “comprise of” is correct. In standard formal English, “comprise” should not be followed by “of”; instead, we say “X comprises Y and Z” or “X is comprised of Y and Z” (passive). As a result, some candidates may wrongly assume that “comprises seven floors…” is incorrect and mark part (1) as the error, even though it is actually the correct formal pattern.

Final Answer:
The sentence is grammatically correct as written, so the answer is No Error, corresponding to part (4).