Answer:
C.

Explanation:
We have been given that the expression
represents number of red carnation plants and expression
represents number of white carnation plants in a section with y sprinklers in a green house.
To find the simplified expression that represents the total number of red and white carnation plants in a section with y sprinklers, we will add our both expressions.

Upon distributing y on 1st expression we will get,


Upon expanding the perfect square we will get,



Now, we will combine like terms.


Therefore, option C is the correct choice.