Final answer:
Human activities have contributed to global temperature increases. The correct answer is option A.
Step-by-step explanation:
The Intergovernmental Panel on Climate Change (IPCC) has determined that human activities have contributed to global temperature increases.
Since the Industrial Revolution, human activity, such as the burning of fossil fuels and deforestation, has increased the amount of greenhouse gases in the atmosphere. These greenhouse gases trap heat energy emitted from the earth's surface, leading to increases in global temperatures and climate change.
It is important to note that the IPCC and the majority of climate scientists agree that human activities are the primary cause of global warming.