Find out the appropriate pronouns for noun.
John and Jacob

The correct answer is: They

In the above sentence we will use 'they' because  I/me, they/them, he/him, she/her, we/us, are personal pronouns. Personal pronouns are pronouns that refer to specific individuals and groups. Whenever we want to use a pronouns other than human beings then we use 'it' in that case, for human beings we use 'He/she'. Here, the groups are referred 'John and Jacob' and so, we use 'they'.