Final answer:
A fjord is formed when sea level rises and fills a glacial valley. An arete, estuary, and tarn also represent specific geographical features resulting from the actions of glaciers. Phytoplankton are more likely to grow in a lake due to their photosynthetic nature and need for sunlight.
Step-by-step explanation:
When sea level rises, causing ocean water to fill a glacial valley, a c) fjord is formed. A fjord is a long, deep, narrow body of water that reaches far inland. Fjords were formed when glaciers retreat, allowing the sea to fill in the valley they carved out. This type of valley is typically found along the coast and is filled with a mixture of fresh water and seawater, creating a unique habitat for various marine species.
An arete is a thin ridge of rock that is left when glaciers erode away at a pass between two valleys. An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. A tarn is a mountain lake or pool, formed in a cirque excavated by a glacier. These terminologies are essential for understanding the results of glaciation and the topographical features of the earth.
Regarding the photosynthetic organisms that are more likely to grow in a lake as opposed to a river, the correct answer would be b) phytoplankton. Phytoplankton are capable of photosynthesis and thrive in still or slowly moving water bodies like lakes because they need light to grow and can more easily remain in the sunlit zone of a lake than in a fast-flowing river.