The two ways of relating what a person has said are 1)direct and 2)indirect (reported speech).In direct speech, the original speaker's exact words are repeated. Direct speech is found in plays and quotations. In indirect/reported speech, the exact meaning is expressed but not necessarily using the original speaker's exact words. Pronouns and possessive adjectives usually change from first or second person to the third person except when the speaker is reporting his own words. Sometimes a noun can be inserted to avoid doubt.
Option D is correct as the given question is transformed to the assertive form, to which is used to join the two statements , present perfect tense is changed to past perfect tense, and if is used as the given question doesn't start with a question word.
Options A,B, and C are wrong as 'is' , 'a room' can not be used and 'if' is not used respectively.
The correct answer is D)Ann asked the receptionist if she had got the room for that night to which the receptionist replied that the hotel was full.