Questions: Why was the Cave of Lascaux closed to the public in 1963? (2 points) The floor of the cave was becoming eroded. Colonies of algae and a calcite veil were developing on the cave walls. Visitors were inadvertently smudging artwork. Both A and B.

The answer is both A and B.

This is a correct statement. The presence of numerous visitors led to physical changes in the cave environment, including erosion of the floor due to foot traffic.

This is also a correct statement. The artificial lighting and increased carbon dioxide levels from visitors contributed to the growth of algae and the formation of a calcite veil on the cave walls, which threatened the preservation of the prehistoric artwork.

While visitors could potentially damage the artwork, the primary reasons for closing the cave were related to environmental changes rather than direct physical contact with the paintings.

This option correctly identifies the two main reasons for the closure of the Cave of Lascaux to the public in 1963.