Final answer:
Japanese emperors claimed to be descended from 3) the sun goddess Amaterasu, and this ancestral connection was institutionalized through Shinto practices and emphasized by rulers.
Step-by-step explanation:
Japanese emperors claimed to be descended from 3) the sun goddess, Amaterasu. The Yamato clan, which began to dominate Honshu during the Kofun period, traced their lineage back to this deity.
Amaterasu was made the top god in a Shinto pantheon to institutionalize the imperial descent, and her worship was central to Shinto practices.
The connection between the imperial family and Amaterasu was emphasized by rulers such as Temmu and Jitō, who used the title 'tennō', affirming their divine descent.