Поставьте прилагательные в нужной форме помогите пж

1. John is the ... in our class.
a. taller;
b. tallest;
c. tall.
2. My grandfather is ... than me grandmother.
a. old;
b. the oldest;
c. older.
3. The elephant is ... than the mouse.
a. the biggest;
b. big;
c. bigger.