Which word in the above sentence is an abstract noun?

Here are the answers to your questions:

4.1)
An abstract noun refers to a quality, concept, idea, or state rather than a physical object. In the given sentence, 'growth' represents a concept or state of developing, which cannot be perceived by the five senses.

The correct option is B.
B) growth

4.2)
A statement is a sentence that declares something, providing information or expressing a fact or opinion. The sentence "Eagles have very sharp vision" presents a fact about eagles.

The correct option is C.
C) statement