Question

soil that is permanently frozen year round is called which of the following? undulation encroachment fragmentation permafrost

Explanation:

To solve this, we analyze each option:

• "undulation" refers to a wavy pattern, not related to frozen soil.
• "encroachment" is about intrusion, not soil freezing.
• "fragmentation" is about breaking into parts, irrelevant here.
• "permafrost" is defined as soil (or rock) that remains permanently frozen year - round, matching the question's description.

Answer:

D. permafrost (assuming the options are labeled A - D as undulation, encroachment, fragmentation, permafrost respectively)