Answer: Option B
Answer: (b)
The correct sequence of divine powers of Rigveda is Indra, Agni, Varuna and Soma.
Indra: Indra was the most important divinity and was lord of war. 250 hymns have been devoted to only Indra in Rigveda, which is highest for any of the gods. His other names are: Car-warrior (Rathestha); A winner (Jitendra) and Soma Drinker (Somapa).
Agni: Agni is the god of fire and acceptor of sacrifices. He was considered to be an intermediary between gods and men. 200 hymns have been devoted to only Agni in Rigveda while Agni is mentioned in 218 hymns.
Varuna: Varuna is the god of the sky, of water and of the celestial ocean, as well as a god of law called Rita, and of the Patal Loka (Under world). He is one of the most prominent Devas in the Rigveda, and lord of the heavens and the earth. 46 hymns are dedicated to Varuna in Rigveda.
Soma: Soma was prepared by extracting juice from the stalks of a certain plant, and the Soma god was god of the plants. 123 hymns are dedicated to Soma and most of them are from Soma Mandala.
Visvedevas: They are various Vedic gods taken together as a whole headed by Indra. 70 hymns are dedicated to Visvedevas in Rigveda.
Yama: Yama is considered to have been the first mortal who died and espied the way to the celestial abodes, and in virtue of precedence, he became the ruler of the departed. He is the guardian of the world of dead. His twin sister is Yami and both Yama and Yami are children of Surya.
Surya: Surya is the Sun god and 8 hymns are dedicated to Surya in Rig-Veda.
Other Rigvedic gods:
Savitri: The Gayatri Mantra is dedicated to Savitri.
Pusan: The guardian of the Jungle Paths and Roads.
Vishnu: A comparatively minor god in Rigveda.
Vayu: Wind god
Dyaus: Father of heaven 
Aditi: Goddess of eternity
Maruts: Storm spirits
Gandhrava: Divine musicians
Ashvins: Divine doctors
Rbhus: Three semi-divine deities of Rigveda.