What were the two watershed developments around 1986 that became cent…

The correct answer is Option (2) → Shah Bano case and Ayodhya issue

The two developments around 1986 that became central to the politics of the BJP were the Shah Bano case (1985) and the Ayodhya issue.

Option (1) Rise of price of essential commodities and the uncertainty in political succession after the death of Indira Gandhi. — Incorrect. Prices rose sharply in 1973 and 1974, and this economic hardship was part of the background to the Emergency, not to the BJP’s politics after 1986. Neither this nor the question of succession was one of the two developments around 1986 that became central to the BJP; those were the Shah Bano case and the Ayodhya issue.

Option (3) The Basic Structure judgment and the demolition of the Babri Masjid — Incorrect. The Basic Structure judgment was the Supreme Court’s decision of 1973 in the Keshavananda Bharati case, that the Constitution has some basic features which the Parliament cannot amend; it belongs to the conflict between the government and the judiciary before the Emergency. The demolition of the structure at Ayodhya came later, in 1992, as an outcome of the Ayodhya issue, so it is not one of the two developments around 1986.

Option (4) Narmada Bachao Andolan and the rise of Hindutva — Incorrect. The Narmada Bachao Andolan is an anti-dam, pro-river movement, not a development in the politics of the BJP. Hindutva was the ideology the BJP pursued for political mobilisation, not one of the two developments of 1986.