The reducing agent in a material is the one that a. gains electrons. b. increases its atomic number. c. is reduced. d. is oxidized.

Answer is: D. is oxidized.

Reducing agent is an element  or compound that loses an electron to another chemical species in a redox chemical reaction and they have been oxidized.

For example, chemical equation: Ca + H₃PO₄ → Ca₃(PO₄)₂ + H₂.

Oxidation reaction: Ca⁰ → Ca⁺² + 2e⁻ /×3.

3Ca⁰ → 3Ca⁺² + 6e⁻

Reduction reaction: 6e⁻ + 2H₃⁺¹ → 3H₂⁰.

Balanced chemical equation: 3Ca + 2H₃PO₄ → Ca₃(PO₄)₂ + 3H₂.

Calcium is stronger reducing agent than hydrogen, gives electrons easier.

Calcium is oxidized, it changes oxidation number from 0 to +2.

it forms an anion that has a larger radius. anions have a negative charge and are larger than the original atom.

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them