The brain's suprachiasmatic nucleus regulates the body's circadian rhythms. The suprachiasmatic nucleus is a minute region of the brain located in the hypothalamus above the optic chiasm, the circadian rhythm is the 24-hour cycle of organisms, related to sunlight and temperature.
Answer: A. cooled and hardened lava from volcanoes
C. sediments deposited by rivers and ocean currents
An accretion is a process in which new materials are added to a tectonic plate or landmass. This process causes the enlargement of the landmass. The materials being added includes sediments, lava from volcanic eruptions and other materials from other sources.
The process of accretion can enlarge the size of a continent along its edge. The new land comes from the cooled and hardened lava from volcanoes and other reason is sediments deposited by rivers and ocean currents.