In the following sentence, identify the part that contains a grammatical error: "Essay writing is an art that requires many planning on the part of the writer."

Introduction / Context:
This question focuses on correct usage of quantifiers with uncountable nouns in English grammar. The sentence describes essay writing as an art and mentions the kind of planning it requires. You need to identify which part uses an inappropriate quantifier with the noun planning.

Given Data / Assumptions:
The sentence segments are:

• A: Essay writing is an art
• B: that requires many planning
• C: on the part of the writer.
• D: No error

We assume formal English usage.

Concept / Approach:
In English, nouns can be countable or uncountable. Planning is an abstract uncountable noun when it refers to the general process or activity of making plans. With uncountable nouns we do not use many. Instead, we use much, a lot of, plenty of, or similar expressions. Therefore, the phrase many planning is incorrect. A correct version would be much planning or a lot of planning.

Step-by-Step Solution:
Step 1: Read the clause Essay writing is an art. This is grammatically correct and sets the context. Step 2: Examine the clause that requires many planning. The noun planning refers to an activity, not individual countable items. Step 3: Recognise that planning is uncountable, just like advice, information, or furniture. Step 4: The quantifier many is used with countable plural nouns such as many books or many ideas. Step 5: For an uncountable noun, the correct quantifier would be much planning or a lot of planning. Step 6: Therefore, the error lies in part B, which should be corrected to that requires much planning or that requires a lot of planning.

Verification / Alternative check:
Rewrite the complete sentence using the correct form: Essay writing is an art that requires much planning on the part of the writer. This version sounds natural and follows standard grammar rules. You could also say that requires a great deal of planning. Both alternatives confirm that the word many is inappropriate with this uncountable noun.

Why Other Options Are Wrong:
Option A, Essay writing is an art, is a correct statement with no grammatical error. Option C, on the part of the writer, is a standard expression showing who must do the planning. Option D, No error, is incorrect because we have clearly identified a quantifier mistake in part B. Thus, only part B contains the grammatical error.

Common Pitfalls:
Students sometimes assume that any noun ending in ing is automatically countable because it looks like an action that could happen many times. However, in grammar, words like planning, teaching, or reading are often uncountable when we refer to the general activity. Using many before an uncountable noun is a frequent error. A good habit is to memorise groups of uncountable abstract nouns and always use much or a lot of with them instead of many.

Final Answer:
The part containing the error is that requires many planning, that is, part B.