Final answer:
Multiplication is the operation defined on the set of nonzero complex numbers.
Step-by-step explanation:
The operation defined on the set of nonzero complex numbers is Multiplication. Complex numbers are expressed in the form a + bi, where a and b are real numbers and i represents the imaginary unit. To multiply complex numbers, we use the distributive property and simplify. For example, (2 + 3i) * (4 - 5i) = 8 - 10i + 12i - 15i^2 = 8 + 2i + 15 = 23 + 2i.