Direction: Fill in the blank in the following sentence with the help of…

Concept:

The verb 'avail' is used in the fixed idiomatic construction 'avail oneself of something', meaning to make use of an opportunity or facility. In this idiom, 'avail' is used reflexively, so it must be followed by a reflexive pronoun (myself, yourself, himself, herself, itself, ourselves, yourselves, themselves) that agrees with the subject in person and number — never a personal object pronoun, a possessive pronoun, or no pronoun at all.

Application:

The subject of the sentence is 'Guests', which is third-person plural. To agree with this subject, the reflexive pronoun must also be third-person plural, i.e. 'themselves'. Filling the blank gives: 'Guests are encouraged to avail themselves of all the hotel facilities.'

Cross-check — why the other options do not fit:

• 'theirs' is a possessive pronoun (showing ownership); the idiom needs a reflexive pronoun, not a possessive one.

• 'them' is a personal object pronoun, not a reflexive pronoun; the idiom specifically requires the reflexive form agreeing with the subject.

• Leaving the blank empty ('no pronoun is required') breaks the fixed idiom, which always takes an explicit reflexive pronoun after 'avail'.

Result:

'themselves' is the reflexive pronoun that correctly completes the idiom and the sentence.