There must be lively discussion of Indian authors if we are to foster our national literature.

Answer: Option A

Promote : support or actively encourage (a cause, venture, etc.); further the progress of.
Cherish : protect and care for (someone) lovingly.
Nourish : provide with the food or other substances necessary for growth, health, and good condition.
Nurture : care for and protect (someone or something) while they are growing.
Foster : encourage the development of (something, especially something desirable).

Synonym of Foster is Promote