Which word does NOT belong with the others?

A peninsula, island, and cape are all landforms; a bay is a body of water.

The core, seeds, and pulp are all parts of an apple. A slice would be a piece taken out of an apple.

The wing, fin, and rudder are all parts of an airplane.

In this series, the letters progress by 1; the numbers decrease by 3.

This is a simple multiplication series. Each number is 2 times greater than the previous number.

Unique, rare, and exceptional are all synonyms. Beautiful has a different meaning.

Acute, right, and obtuse are geometric terms describing particular angles. Parallel refers to two lines that never intersect.

A circle, oval, and sphere are all circular shapes with no angles. A triangle is a different kind of shape with angles and three straight sides.

The scythe, knife, and saw are all cutting tools. Pliers are tools, but they are not used for cutting.

Biology, chemistry, and zoology are all branches of science. Theology is the study of religion.