Concept:
The history of Buddhism is closely connected with several important kings and emperors of ancient India. To determine the correct sequence, we must arrange these rulers chronologically according to the dynasties and historical periods in which they lived.
Step 1: Understanding the period of Bimbisāra and Ajātaśatru.
• Bimbisāra was the ruler of the Haryanka dynasty of Magadha during the lifetime of Gautama Buddha. He was one of the earliest royal patrons of Buddhism and donated the famous Veluvana monastery to the Buddha.
• Ajātaśatru, the son of Bimbisāra, succeeded him on the throne. Although initially influenced by Devadatta, he later became a supporter of the Buddha and played a major role in the First Buddhist Council after the Buddha’s Mahāparinirvāṇa.
Therefore:
\[
\text{Bimbisāra} \rightarrow \text{Ajātaśatru}
\]
Thus:
\[
B \rightarrow E
\]
Step 2: Understanding the place of Kālāśoka.
Kālāśoka belonged to the Śiśunāga dynasty and ruled after the Haryanka rulers. He is historically important because the Second Buddhist Council was held during his reign at Vaiśālī.
Hence, Kālāśoka comes after Ajātaśatru.
\[
B \rightarrow E \rightarrow A
\]
Step 3: Understanding the position of Emperor Aśoka.
Emperor Aśoka belonged to the Maurya dynasty and ruled much later than Kālāśoka. After the Kalinga war, he accepted Buddhism and spread the Dharma throughout Asia. He organized the Third Buddhist Council and sent Buddhist missionaries to many countries.
Therefore, Aśoka comes after Kālāśoka.
\[
B \rightarrow E \rightarrow A \rightarrow D
\]
Step 4: Understanding the period of Kumāragupta.
Kumāragupta belonged to the Gupta dynasty, which flourished many centuries after the Mauryan Empire. He is traditionally associated with the development and patronage of Nālandā Mahāvihāra.
Hence, Kumāragupta comes last among the given rulers.
\[
B \rightarrow E \rightarrow A \rightarrow D \rightarrow C
\]
Step 5: Final chronological arrangement.
The complete correct sequence is:
\[
\boxed{B, E, A, D, C}
\]
Therefore, Option (3) is correct.