The Question Below Refers to the Following Information Figure 451
-Which of the Following Is Secreted by the Pineal

The question below refers to the following information.
In an experiment, rats' ovaries were removed immediately after impregnation and then the rats were divided into two groups. Treatments and results are summarized in the table below
$\begin{array}{lcc}\hline&\text { Group } 1 &\text { Group } 2\\\hline (\text { Daily injections of }&&\\\text { progesterone (milligrams) } & 0.25 & 2.0 \\\text { Percentage of rats that } & & \\\text { carried fetuses to birth } & 0 & 100\\\hline\end{array}$

Figure 45.1
-Which of the following is secreted by the pineal gland?

A) androgens
B) estrogens
C) progestins
D) catecholamines
E) melatonin