Relating to or denoting glands which secrete hormones or other products directly into the blood.

ANSWER (B) IS CORRECT.

Endocrine glands are called ductless glands.

Explanation:
- Endocrine glands are a type of glands that secrete hormones directly into the bloodstream without the use of ducts.
- These glands are referred to as ductless glands because they do not have ducts to transport their secretions.
- The hormones secreted by the endocrine glands are released directly into the bloodstream, allowing them to reach their target organs or tissues through circulation.
- Some examples of endocrine glands include the pituitary gland, thyroid gland, adrenal glands, pancreas, and ovaries/testes.
- These glands play a crucial role in maintaining homeostasis and regulating various bodily functions such as metabolism, growth and development, reproduction, and response to stress.
- The secretions of endocrine glands, i.e., hormones, act as chemical messengers that bind to specific receptors on target cells, thereby regulating their activity.
- Unlike endocrine glands, exocrine glands have ducts that transport their secretions to specific locations, such as the surface of the body or the lumen of a hollow organ.
- Examples of exocrine glands include sweat glands, salivary glands, and digestive glands.
- Exocrine glands secrete substances such as sweat, saliva, and digestive enzymes through ducts.
- The sweat glands mentioned in option 'a' are exocrine glands, not endocrine glands, as they release sweat through ducts onto the skin's surface.
- Hence, the correct answer is option 'b' - endocrine glands.