Read the passage and answer the question:

When the king Devanampiya Piyadassi had been ruling for eight years, the (country of the) Kalingas (presentday coastal Orissa) was conquered by (him). One hundred and fifty thousand men were deported, a hundred thousand were killed, and many more died. After that, now that (the country of) the Kalingas has been taken, Devanampiya (is devoted) to an intense study of Dhamma, to the love of Dhamma, and to instructing (the people) in Dhamma. This is the repentance of Devanampiya on account of his conquest of the (country of the) Kalingas.

For this is considered very painful and deplorable by Devanampiya that, while one is conquering an unconquered (country) slaughter, death and deportation of people (take place) there …

What event triggered King Devanampiya's intense study and dedication to Dhamma?

The conquest of the country of Kalingas

The correct answer is Option 4 - The conquest of the country of Kalingas

As per the passage:

After that, now that (the country of) the Kalingas has been taken, Devanampiya (is devoted) to an intense study of Dhamma, to the love of Dhamma, and to instructing (the people) in Dhamma. This is the repentance of Devanampiya on account of his conquest of the (country of the) Kalingas.

Asoka and his Dhamma:

Asoka was the first ruler who inscribed his messages to his subjects and officials on stone surfaces – natural rocks as well as polished pillars. He used the inscriptions to proclaim what he understood to be dhamma. This included respect towards elders, generosity towards Brahmanas and those who renounced worldly life, treating slaves and servants kindly, and respect for religions and traditions other than one’s own. Asoka also tried to hold his empire together by propagating dhamma, the principles of which were simple and virtually universally applicable. This, according to him, would ensure the well-being of people in this world and the next. Special officers, known as the dhamma mahamatta, were appointed to spread the message of dhamma.