Which organ among the following does not represent an accessory digestive organ?

The correct option is D Stomach

$\bullet$ Accessory digestive organs are organs help in digestion, but are not a part of the digestive system.
$\bullet$ The salivary glands, pancreas, liver and gallbladder are accessory digestive organs, i.e., they not part of the digestive system but release their secretion into the digestive tract. These secretions are essential for digestion.
$\bullet$ Stomach is part of the digestive system, which secretes enzymes and hydrocjloric acid. It holds the food that we consume and is also a site for digestion.