Final answer:
The stage of the estrous cycle that corresponds with pseudopregnancy is Diestrus, which is part of the luteal phase. Option D is correct.
Step-by-step explanation:
The stage of the estrous cycle that corresponds with pseudopregnancy in non-primate mammals is Diestrus. Pseudopregnancy, or false pregnancy, occurs after the estrus phase when the corpus luteum is still active, producing hormones even though no fertilization has taken place.
During diestrus, if fertilization has not occurred, the corpus luteum regresses, leading to decreased levels of progesterone, which may mimic pregnancy symptoms, hence the term pseudopregnancy. This stage is in the luteal phase of the estrous cycle, analogous to the luteal phase in the menstrual cycle.