The term "chometz" specifically refers to grains that have leavened during the Passover holiday. In Jewish dietary laws, certain grains such as wheat, barley, rye, oats, and spelt are considered chometz if they ferment and rise. This means they cannot be consumed or owned during Passover, as the holiday commemorates the Exodus from Egypt, where the Israelites had to leave quickly and did not have time for their bread to rise. Therefore, any leavened products made from these grains are strictly prohibited throughout the duration of Passover.
The other options do not accurately capture the definition of "chometz." Permissible grains are those that can be consumed during Passover, while unleavened bread, known as "matzah," is specifically acceptable. Special wine may be a part of Passover traditions but has no direct relation to the definition of chometz itself.