When Alexander the great invaded India, the dynasty which was ruling over entire north India was : A. Gupta Dynasty B. Maurya Dynasty C. Sakya Dynasty D. Nanda Dynasty

The correct answer is: D. Nanda Dynasty

The Nanda Dynasty was the last major Indian dynasty before the rise of the Mauryan Empire. They ruled over most of northern India from around 345 to 321 BCE.

The Nandas were a powerful and wealthy dynasty. They were known for their military prowess and their administrative skills. They built a large and efficient army and bureaucracy. They also built many roads, canals, and irrigation systems.

The Nandas were overthrown by Chandragupta Maurya, the founder of the Mauryan Empire.

The other options are incorrect:

• The Gupta Dynasty ruled over northern India from around 320 to 550 CE.
• The Maurya Dynasty ruled over northern India from around 321 to 185 BCE.
• The Sakya Dynasty was a small kingdom in northern India that ruled from around 600 to 486 BCE.