Which statement best describes how ductless glands secrete hormones?

• A. They release hormones into ducts
• B. They produce mucus
• C. They release enzymes
• D. They release hormones directly into the bloodstream

Answer: (D)

Ductless glands are endocrine glands that release hormones directly into the bloodstream, since they lack ducts. The hormones travel through the blood to distant target tissues where they elicit specific effects. Releasing into ducts would describe exocrine glands, and producing mucus or secreting enzymes pertains to non-endocrine functions, not how ductless glands operate.