Enamel is a hard, protective outer layer that covers the crown of a tooth. It is the hardest substance in the human body and helps to protect the underlying layers of the tooth from damage and decay. Option 1 correctly states that enamel covers the crown of the tooth. The crown is the visible part of the tooth that is above the gum line.

Option 2 is incorrect because enamel does not cover the dentin on all sides. Dentin is a layer of hard tissue that lies beneath the enamel and makes up the majority of the tooth structure.

Option 3 is incorrect because enamel does not cover cementum. Cementum is a hard, bony tissue that covers the root of the tooth and helps to anchor it to the jawbone.

Similarly, option 4 is incorrect because enamel does not cover cementum and only partially covers dentin.