Choose the correct sequence to form a meaningful sentence:
(A) opened  
(B) slowly  
(C) the door  
(D) he

Correct option is B

Option (b) DACB is correct.
Explanation: Standard English word order is Subject + Verb + Object + (Adverbial). Mapping the parts: D (he) = Subject, A (opened) = Verb, C (the door) = Object, B (slowly) = Adverbial → He opened the door slowly.
· Why others are wrong:
· (b) DABC: invalid.
· (c) BACD: starts with an adverb, then a verb, then object, then subject → Slowly opened the door he (ungrammatical).
· (d) DCAB: He the door opened slowly places the object before the verb without a structure that permits such inversion—ungrammatical in simple declaratives.