Parts of a sentence are given below in jumbled order. Arrange the parts in the…

Concept

In sentence rearrangement, begin with a grammatically independent subject phrase, then attach the finite verb or complement it requires. Linkers such as “and” join parallel actions, while modifiers stay beside the word or action they complete.

Application

1. A supplies the subject phrase “the best defence against allergies”.

2. C begins with “is to”, which completes that subject, and continues with “avoid the triggers whenever”.

3. B begins with “possible”, completing the fixed phrase “whenever possible”, and then adds the parallel action “promptly take anti-allergy”.

4. D supplies the noun and time phrase “medications after exposure”, completing “take anti-allergy medications after exposure”.

Cross-check and contrast

Reading ACBD gives: “The best defence against allergies is to avoid the triggers whenever possible and promptly take anti-allergy medications after exposure.” The subject, verb, paired actions, and modifiers connect without a grammatical break.

• BADC opens with “possible”, so it begins with a dependent continuation rather than a complete subject.

• CDBA opens with “is to” before introducing the subject that the verb needs.

• DBAC opens with “medications after exposure” and later separates “whenever” from “possible”.

Result

Therefore, the meaningful sequence is ACBD.