Which of the following sentences uses "their" correctly?

My best friend, Jamie, said she would never go their again.

The sixth grade students studied the rules before their test.

Sandrice loves her grandparents; their her favorite people.

Their ready for the field trip to the Museum of Natural History.

Question

Which of the following sentences uses "their" correctly? 

My best friend, Jamie, said she would never go their again. 

The sixth grade students studied the rules before their test.

Sandrice loves her grandparents; their her favorite people. 

Their ready for the field trip to the Museum of Natural History.

anonymous · Answer

@MasonP 
@jamesr
@jacobciezki   
@AeroSmith 
@Afrodiddle 
@Lunalovegood 
@ali2x2 HELP ME PLZZZ

anonymous · Answer

@redheadangel help me 
@Samidancer16 
@Summersnow8
@LexiLuvv2431

anonymous · Answer

It is B :)

redheadangel · Answer

I agree with @LexiLuvv2431

redheadangel · Answer

Because it belongs to them

anonymous · Answer

A is wrong. It should be there
C is wrong. It shoud be they're or they are and the same for D. Their shows possession. that is Their test

anonymous · Answer

@LexiLuvv2431 thx I have more but im gonna answer ur questions 1 k

anonymous · Answer

Okayy. I'm really good at english annd stuff like that :)

anonymous · Answer

I have another question so do you want to ask yours so I can ask mine?