Which of the following incident brought the factional rivalry between the Syndicate and Indira Gandhi in the open?

Presidential election, 1969

The factional rivalry between the Syndicate and Indira Gandhi came in the open in 1969 Presidential elections.

The factional rivalry between the Syndicate and Indira Gandhi came to a head in 1969, marked by a significant event. Following the passing of President Zakir Hussain, the vacancy for the President of India emerged that year. Despite Indira Gandhi's reservations, the 'Syndicate,' a group within the Indian National Congress, successfully nominated her longstanding political rival and then-Speaker of the Lok Sabha, N. Sanjeeva Reddy, as the official Congress candidate for the upcoming Presidential elections.
In response, Indira Gandhi took a decisive stance by urging the Vice-President at the time, V.V. Giri, to enter the race as an independent candidate. Simultaneously, she introduced several noteworthy and popular policy initiatives, including the nationalization of fourteen prominent private banks and the abolition of the 'privy purse'.