The correct answer is: a) Nagarjunakonda.
Nagarjunakonda is an archaeological site in Guntur district of Andhra Pradesh, India. It was a Buddhist university and monastic center from the 3rd to the 6th centuries CE. The site is known for its well-preserved stupas, monasteries, and temples.
Evidence of early agricultural practices has been found at the site. This includes tools used for farming, such as axes and hoes, as well as seeds and grains. The presence of these items suggests that the people of Nagarjunakonda were engaged in agriculture.
The other options are incorrect. Peddamudiyam is an archaeological site in Prakasam district of Andhra Pradesh, India. It is known for its megalithic tombs. Amaravati is an archaeological site in Guntur district of Andhra Pradesh, India. It was a Buddhist capital from the 3rd to the 6th centuries CE. Salihundam is an archaeological site in East Godavari district of Andhra Pradesh, India. It is known for its Buddhist stupas and temples.