Read the sentence.
What is the agreement error in this sentence?
No one could believe their luck when the owner of the
restaurant offered free dessert to all,
The pronoun "their" does not match its antecedent in
number.
The pronoun their" does not match its antecedent in
person.
The pronoun "their" does not match its antecedent in case
or number.
The pronoun "their" does not match its antecedent in
number or person.