Choose the word which is different from the rest.

The answer is D. Peso.

The other four options are Greek letters. The peso is a unit of currency used in several countries, including Argentina, Chile, Colombia, Mexico, and the Philippines.

Phi (Φ) is the 21st letter of the Greek alphabet. It is used to represent the golden ratio, which is a special number approximately equal to 1.618.

Gamma (Γ) is the third letter of the Greek alphabet. It is used to represent the gamma function, which is a function that is defined for all complex numbers except for the non-positive integers.

Delta (Δ) is the fourth letter of the Greek alphabet. It is used to represent the change in a quantity, as well as the Laplace operator.

Beta (β) is the second letter of the Greek alphabet. It is used to represent the beta function, which is a function that is defined for all complex numbers except for the non-positive integers.