Select the most appropriate option that can substitute the highlighted segment in the given sentence. If there is no need to substitute it, select ‘No substitution required’.
Rosie became an expert in the field of painting by her.

Correct option is B

The correct substitution of the highlighted words is (b) painting by herself.
Explanation: The original phrase “by her” is vague and ungrammatical in this context.
The correct reflexive form is “by herself” and the gerund form “painting” is required to describe the action.
Grammatical Rule Used: Use of reflexive pronouns (myself, herself, themselves, etc.) to show the subject is both the doer and receiver of the action. Gerunds (verb+ing) function as nouns.
Example: He learned driving by himself.
Information Booster: Reflexive pronouns must match the subject of the sentence and gerunds are required after prepositions like "of."