The layer of the Earth that surrounds and protects us from dangerous rays from the Sun is the atmosphere (option A). The atmosphere is a layer of gases that envelops the Earth and acts as a shield against harmful solar radiation. It contains various components such as nitrogen, oxygen, carbon dioxide, and trace amounts of other gases. The ozone layer, located within the atmosphere's stratosphere, plays a crucial role in filtering out harmful ultraviolet (UV) rays from the Sun. The atmosphere also helps regulate temperature and weather patterns, making it an essential protective layer for life on Earth. While the other options mentioned (biosphere, hydrosphere, and lithosphere) are significant components of the Earth's systems, they do not directly shield us from dangerous rays from the Sun.