Part B has an error.
The adjective 'careful' should be replaced with the adverb 'carefully'. An adjective cannot qualify the verb 'notice', but an adverb can.
Hence, option (c) is the correct answer.
Note:
Adjectives: Words which are used with a noun/pronoun to describe or point out, the person, animal, place, or thing which the noun names, or to tell the number or quantity, are called Adjectives.
Adverbs: Words that describe a verb, an adjective, another adverb, or even a sentence as a whole are called Adverbs.
Study Notes
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