Is the simple subject a noun verb adjective adverb or a preposition?

The simple subject is a noun or a pronoun. Examples:

Mom made lunch. (the simple subject is 'mom')

Jason's mom made lunch. (the subject is 'Jason's mom', the simple subject is 'mom')

Someone from the church committee made lunch. (the subject is 'someone from the church committee is the subject, the simple subject is 'someone')