Concept:'Vixen' is the feminine form of 'fox'. In English, some animals have different names for male and female, but for the fox, the male is also called a fox.
Explanation:A vixen specifically means a female fox. To determine its masculine gender, we need the male counterpart. For the species 'fox', the male is simply referred to as a fox, without a separate word. Among the given options: Option A, 'ox', is a male bovine animal, not related. Option B, 'fox', is the correct masculine form. Option C, 'horse', is a different animal; its masculine is stallion. Option D, 'deer', does not match; a male deer is a buck or stag. Therefore, the masculine gender of vixen is fox. This pattern occurs in many animals: for example, a female tiger is a tigress, and the male is tiger; a female lion is a lioness, and the male is lion. Similarly, a female fox is a vixen, and the male is fox.
Answer:The correct answer is fox, which corresponds to option B.