The correct option is B Fourth five year plan
In 1965, when fourth plan was to be launched, Indo-Pakistan conflict led to war. The Pakistan favouring countries like US and others withdrew foreign aid to India. Again in 1966, due to drought, there was food shortage. The Indian government had to take help from USA and they were helped leading to financial crisis more severe. Amidst of these conditions, fourth five year plan was launched in 1969.