The correct answer is B: I, II and III.
The key points agreed upon at the Earth Summit, held in Johannesburg in 2002, included:
I. To halve the proportion of people without access to proper sanitation by 2015: This was a significant goal aimed at improving sanitation and public health worldwide.
II. To cut significantly the rate at which rare animals and plants are becoming extinct by 2010: This commitment highlighted the need for biodiversity conservation.
III. To initiate strategies to preserve resources for future generations by 2005: This focused on sustainable development and resource management.
IV. To increase the share of world energy produced from renewable 'green' sources such as solar or wind power: While this was a crucial goal, it was not specifically listed among the agreed points for the summit's immediate goals.
Thus, options I, II, and III are accurate representations of the commitments made during the summit.