The gestation period of mare is

Answer: Option D

The gestation period of mare is 340 days.
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). The time interval of a gestation is called the gestation period.
Pregnancy in the horse is typically accepted as varying from 335 - 342 days however, on the odd occasion, can range from as little as 315 to over 400 days. The foal does the majority of its growth towards the end of gestation with $${\frac{2}{3}}^{\text{rd}}$$ of this occurring in the last 3 months.