質 quality

These two axes are the best-quality SHIT money can buy.

question ★★★★★
質 (quality) + 問 (question, problem) = 質問 (question)

a question - usually used in a structured setting: interview, trial, test.　

BOOBOO: in casual conversation, people will say 尋ねる　or 聞く instead of 質問.

quality ★★★☆☆
品 (products) + 質 (quality) = 品質 (quality)

quality of merchandise　(品質のいい/品質の悪い）

essential nature ★☆☆☆☆
性 (sex / essential nature) + 質 (quality) = 性質 (essential nature)

natural quality. In contrast to 性格（せいかく）, 性質 applies to rocks and things as well as people and animals. Also it refers to the inner nature of people, rather than their social selves. So if you wanted to say that someone was very outgoing and loved sports and bars, you wouldn't use 性質. But if you wanted to say that someone was very stoic or honest, you would.