In the following sentence, identify the part that contains a grammatical error, or select “No error”: “It was obviously for everyone (A) that grandfather was (B) hiding something from all of us. (C) No error (D).”

Introduction:
Error spotting questions check how accurately you can notice incorrect usage of words, prepositions, and structures in seemingly simple sentences. The given sentence describes a situation where everyone realises that the grandfather is hiding something. Although the overall meaning is clear, one segment uses the wrong form of a word, and your job is to pinpoint that specific part rather than rewriting the whole sentence.

Given Data / Assumptions:

- Part A: It was obviously for everyone - Part B: that grandfather was - Part C: hiding something from all of us. - Part D: No error - Only one segment contains an error in standard English usage.

Concept / Approach:
The key phrase here is obviously for everyone, which sounds unnatural in standard English. The usual expression is obvious to everyone, not obviously for everyone. Obviously is an adverb and is normally used to modify a verb or a whole clause, while obvious is an adjective used with the preposition to in this pattern. Once you recognise this, the rest of the sentence falls into place and appears correct.

Step-by-Step Solution:
Step 1: Read the sentence aloud: It was obviously for everyone that grandfather was hiding something from all of us. Step 2: Focus on the phrase obviously for everyone and compare it with common English usage. Step 3: Recognise that the standard phrase is It was obvious to everyone that..., using the adjective obvious and the preposition to. Step 4: Confirm that Parts B and C are grammatically sound and clearly express that grandfather was hiding something. Step 5: Conclude that the error lies in Part A.

Verification / Alternative check:
Rewrite the sentence correctly: It was obvious to everyone that grandfather was hiding something from all of us. This version is smooth and idiomatic. There is no tense mismatch, and the clause that grandfather was hiding something from all of us correctly follows the introductory phrase. Because only Part A needed correction, the other parts are error free.

Why Other Options Are Wrong:
Part B, that grandfather was, introduces a noun clause and uses the past continuous correctly with hiding in Part C. Part C, hiding something from all of us, is grammatically correct and accurately describes the secretive action. Part D, No error, cannot be chosen because we have already identified a clear mistake in Part A. Therefore, options B, C, and D are all incorrect choices for this question.

Common Pitfalls:
Candidates often overlook small preposition and adjective errors when the overall meaning is clear. Another common trap is focusing on later parts of the sentence and suspecting the tense or the clause connector. To avoid this, always check collocations such as obvious to everyone, proud of someone, or angry with someone, because they follow fixed patterns in English. Familiarity with these patterns makes it easier to spot errors like obviously for everyone quickly.

Final Answer:
A is the part that contains the grammatical error.