Question

what is the definition for isthmus?
long, but narrow, topographical depression
group of islands
formed by sediment from plant and animal remains
narrow strip of land connecting two landmasses

Explanation:

To determine the definition of "isthmus", we analyze each option:

• "Long, but narrow, topographical depression" describes a valley or similar, not an isthmus.
• "Group of islands" is an archipelago, not an isthmus.
• "Formed by sediment from plant and animal remains" refers to something like a fossil - fuel - forming process or a different geological formation, not an isthmus.
• "Narrow strip of land connecting two landmasses" matches the standard definition of an isthmus.

Answer:

D. Narrow strip of land connecting two landmasses (assuming the last option is labeled D; if the original options had different labels, adjust the label accordingly based on the last option's position)