The plural of deer is deer. This word is an irregular plural noun The noun deer is both the singular and the plural They saw one deer or They saw two million deer Deer is the preferred plural form of deer, although deers (rarely used) is also an accepted plural.

Hint: Deer is a four-legged animal. Some nouns do not change when pluralized.Complete answer: There are many words in the English language which are used unaltered to refer to singular or plural nouns. For e.g., Sheep, series, news, etc. These words refer to both singular forms of the noun as well as the plural form as needed. Deer is one such word too. It is used as per the requirement for both singular as well as plural. Thus, option d, Deer is the correct answer. Option b, dears is the plural of the word dear which is used as an affectionate or friendly form of address. For e.g. Dear mother or ‘My dears’ (used to refer to a group of people who are dear to someone). Hence, option b is incorrect. There is no such word as ‘deeres’ in the English language, therefore, option c too is incorrect.Note: To refer to more than one deer, we can say, two deer, ten deer, 100 deer, etc. we do not say two deers, or ten deers as that would be incorrect.

Deer. however I've heard people say reindeers. I don't believe it's correct.