Rearrange the following parts to construct a contextually and grammatically correct sentence.

(A) for reducing

(B) urban traffic congestion

(C) approved a new scheme

(D) the municipal corporation

The correct answer is DCAB.

To construct a contextually and grammatically correct sentence, we need to arrange the given parts in a logical sequence:

1. Subject: Part (D) "the municipal corporation" serves as the subject of the sentence, establishing who is performing the action.
2. Verb and Action: Part (C) "approved a new scheme" contains the finite verb "approved" and its direct object "a new scheme", which naturally follows the subject.
3. Prepositional Phrase / Purpose: Part (A) "for reducing" introduces the prepositional phrase that describes the intent or reason behind approving the new scheme.
4. Object of Preposition: Part (B) "urban traffic congestion" provides the noun phrase that functions as the object of the gerund "reducing", specifying what problem is to be mitigated.

Putting these parts together in the order (D) → (C) → (A) → (B) gives the coherent sentence:
"The municipal corporation approved a new scheme for reducing urban traffic congestion."

Hence, the correct sequence is DCAB.