Which word does NOT belong with the others?

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.

This is a simple subtraction series; each number is 4 less than the previous number.

Two series alternate here, with every third number following a different pattern. In the main series, 3 is added to each number to arrive at the next. In the alternating series, 5 is subtracted from each number to arrive at the next.

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

Fair, just, and equitable are all synonyms meaning impartial. Favorable means expressing approval.

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.