How do you say "I am in high school" In spanish

Which one of the following is the correct rhyme to keep in mind when using the spanish counterparts to this, that, those and these? a: “that” and “those” both have s’s, “this” and “these” don’t b: “that” and “those” both have t’s, “this” and “these” don’t c: “this” and “these” both have s’s, “that” and “those” don’t d: “this” and “these” both have t’s, “that” and “those” don’t