When studying moose foraging behavior, you note that moose spend some time eating aquatic plants even though the leaves of deciduous trees along the shore have higher energy content. what might explain this observation?

Moose is the largest and heaviest species of deer found in mainly Alaska, Canada, some parts of the United States. They are herbivores and feed on leaves, grass, bark, shrubs, and fruits.

Aquatic plants are a great source of protein and salt which is not found in an appropriate amount in leaves of trees but it is important for moss for its growth, therefore, aquatic plants are one of the essential parts of moose diet.

Aquatic plants also have minerals like iron, phosphorus, sulfur, iron, calcium and it also contains crude fibers that attract moose because of its rich nutritional quality.  

Therefore to obtain salt and these variety of nutrients moose spend some time eating aquatic plants which are not present in leaves of deciduous trees.

the answer is b.) hydrogen bonds between bases.