#### Answer

D

#### Work Step by Step

We are asked to find the polynomials that are the opposite of $-y^{5}+10y^{3}-2.3$. Recall that the opposite of a number/term $a$ is the number/term $-a$.
Therefore, if $a=-y^{5}+10y^{3}-2.3$, its opposites will be in the form $-a=-(-y^{5}+10y^{3}-2.3)$
We can use the distributive property to further simplify.
$-a=-1\times(-y^{5}+10y^{3}-2.3)=y^{5}-10y^{3}+2.3$
Therefore, D is the opposite of the given polynomial.