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.
O The pronoun "their" does not match its antecedent in
number
O The pronoun their does not match its antecedent in
person
O The pronoun their" does not match its antecedent in
case or number
O The pronoun "their" does not match its antecedent in
number or person.

the pronoun "their"does not match it's antecedent in number or person

Proposal 2.

The question is obviously incomplete, since it is missing the proposals. I've found them online:

Proposal 1: The best way to get people invested in the library is to show them the joy of reading. For that reason, the library should hold a book sale. People could donate books that they no longer want, and the librarians could find books that the library no longer needs. Volunteers would need to sort the books into categories and arrange them in an inviting way, like at a bookstore. Books should be inexpensive so people will buy more of them – may be fifty cents for paperbacks and two dollars for hardcover books. A book sale would appeal to people of all ages, from little kids to older people. There should also be a table where people can sign up for library cards. That way, if visitors do not find any books they want at the sale, they can come back to the library.

Proposal 2: A great way to make money for the library would be holding a car wash. The softball team at my school raised over $400 at their car wash last year! The car wash could be held in the library parking lot on a Saturday morning. You could ask local high school students to volunteer to wash the cars. That would be a great way to get students involved with the library. It takes two or three volunteers to wash a car quickly, so you would need at least ten volunteers. You could charge around ten dollars per car. Even people who are not very interested in reading like to have a clean car, so you would get a lot of people to stop by who might not otherwise come to a library fundraiser.

After carefully reading the two proposals for a fundraiser to help the library, I have arrived at the resolution that the second proposal is probably going to be progressively effective.

The first proposal makes a wonderful recommendation while welcoming us to attempt to wakeful individuals' enthusiasm for reading books. In any case, it takes something other than a book deal for that to occur. Other than that, the costs recommended to be charged for the books - between fifty cents and two dollars - won't be viable. Our motivation is to fund-raise for the library, so we should think about what will most proficiently have individuals go through their cash.

The second proposal is increasingly compelling in its motivation. Despite the fact that it might sound weird to hold a car wash when the objective is to support a library,car wash are known to collect a decent measure of cash without any problem. Indeed, even individuals who hate perusing at all may wind up aiding, either by chipping in or by having their cars washed. As said in the proposal, relatively few volunteers would be fundamental (just around ten) and we can without much of a stretch discover help when the action is fun and pleasant.